Change 'filename:' for Python 2 (legacy)

Before renaming, all Python 2 filenames were 'learnpython-*.py'.

This commit renames them to 'learnpythonlegacy-*.py'.

To verify that the filenames were named consistently across
translations prior to this commit, and to change this:

```
find . -name "pythonlegacy*.markdown" -exec ack filename: {} \;

find . -name "pythonlegacy*.markdown" -exec \
  sed -i 's/^filename: learnpython/filename: learnpythonlegacy/' {} \;
```

de-de/pythonlegacy-de.html.markdown

@@ -4,7 +4,7 @@ contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
 translators:
     - ["kultprok", "http:/www.kulturproktologie.de"]
-filename: learnpython-de.py
+filename: learnpythonlegacy-de.py
 lang: de-de
 ---
 

es-es/pythonlegacy-es.html.markdown

@@ -6,7 +6,7 @@ translators:
     - ["Camilo Garrido", "http://www.twitter.com/hirohope"]
     - ["Fabio Souto", "http://fabiosouto.me"]
 lang: es-es
-filename: learnpython-es.py
+filename: learnpythonlegacy-es.py
 ---
 
 Python fue creado por Guido Van Rossum en el principio de los 90. Ahora es uno

fr-fr/pythonlegacy-fr.html.markdown

@@ -1,6 +1,6 @@
 ---
 language: Python 2 (legacy)
-filename: learnpython-fr.py
+filename: learnpythonlegacy-fr.py
 contributors:
   - ["Louie Dinh", "http://ldinh.ca"]
 translators:

hu-hu/pythonlegacy-hu.html.markdown

@@ -9,7 +9,7 @@ contributors:
     - ["habi", "http://github.com/habi"]
 translators:
     - ["Tamás Diószegi", "https://github.com/ditam"]
-filename: learnpython-hu.py
+filename: learnpythonlegacy-hu.py
 lang: hu-hu
 ---
 

it-it/pythonlegacy-it.html.markdown

@@ -1,6 +1,6 @@
 ---
 language: Python 2 (legacy)
-filename: learnpython-it.py
+filename: learnpythonlegacy-it.py
 contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
     - ["Amin Bandali", "http://aminbandali.com"]

ko-kr/pythonlegacy-kr.html.markdown

@@ -3,7 +3,7 @@ language: Python 2 (legacy)
 category: language
 contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
-filename: learnpython-ko.py
+filename: learnpythonlegacy-ko.py
 translators:
     - ["wikibook", "http://wikibook.co.kr"]
 lang: ko-kr

pl-pl/pythonlegacy-pl.html.markdown

@@ -2,7 +2,7 @@
 name: python
 category: language
 language: Python 2 (legacy)
-filename: learnpython-pl.py
+filename: learnpythonlegacy-pl.py
 contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
     - ["Amin Bandali", "http://aminbandali.com"]

pt-br/pythonlegacy-pt.html.markdown

@@ -5,7 +5,7 @@ contributors:
 translators:
     - ["Vilson Vieira", "http://automata.cc"]
 lang: pt-br
-filename: learnpython-pt.py
+filename: learnpythonlegacy-pt.py
 ---
 
 Python foi criado por Guido Van Rossum no começo dos anos 90. Atualmente é uma

pythonlegacy.html.markdown

@@ -8,7 +8,7 @@ contributors:
     - ["asyne", "https://github.com/justblah"]
     - ["habi", "http://github.com/habi"]
     - ["Rommel Martinez", "https://ebzzry.io"]
-filename: learnpython.py
+filename: learnpythonlegacy.py
 ---
 
 Python was created by Guido Van Rossum in the early 90s. It is now one of the

ro-ro/pythonlegacy-ro.html.markdown

@@ -4,7 +4,7 @@ contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
 translators:
     - ["Ovidiu Ciule", "https://github.com/ociule"]
-filename: learnpython-ro.py
+filename: learnpythonlegacy-ro.py
 lang: ro-ro
 ---
 

ru-ru/pythonlegacy-ru.html.markdown

@@ -6,7 +6,7 @@ contributors:
 translators:
     - ["Yury Timofeev", "http://twitter.com/gagar1n"]
     - ["Andre Polykanine", "https://github.com/Oire"]
-filename: learnpython-ru.py
+filename: learnpythonlegacy-ru.py
 ---
 
 Язык Python был создан Гвидо ван Россумом в начале 90-х. Сейчас это один из

tr-tr/pythonlegacy-tr.html.markdown

@@ -1,6 +1,6 @@
 ---
 language: Python 2 (legacy)
-filename: learnpython-tr.py
+filename: learnpythonlegacy-tr.py
 contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
 translators:

uk-ua/pythonlegacy-ua.html.markdown

@@ -10,7 +10,7 @@ contributors:
     - ["habi", "http://github.com/habi"]
 translators:
     - ["Oleh Hromiak", "https://github.com/ogroleg"]
-filename: learnpython-ua.py
+filename: learnpythonlegacy-ua.py
 ---
 
 Мову Python створив Гвідо ван Россум на початку 90-х. Наразі це одна з 

zh-cn/pythonlegacy-cn.html.markdown

@@ -4,7 +4,7 @@ contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
 translators:
     - ["Chenbo Li", "http://binarythink.net"]
-filename: learnpython-zh.py
+filename: learnpythonlegacy-zh.py
 lang: zh-cn
 ---
 

zh-tw/pythonlegacy-tw.html.markdown

@@ -7,7 +7,7 @@ contributors:
     - ["evuez", "http://github.com/evuez"]
 translators:
     - ["Michael Yeh", "https://hinet60613.github.io/"]
-filename: learnpython-tw.py
+filename: learnpythonlegacy-tw.py
 lang: zh-tw
 ---