[python3/en] Add empty tuple to "False if evaluated" list (#2587)

python3.html.markdown

@@ -143,13 +143,13 @@ None  # => None
 "etc" is None  # => False
 None is None   # => True
 
-# None, 0, and empty strings/lists/dicts all evaluate to False.
+# None, 0, and empty strings/lists/dicts/tuples all evaluate to False.
 # All other values are True
 bool(0)   # => False
 bool("")  # => False
 bool([])  # => False
 bool({})  # => False
-
+bool(())  # => False
 
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 ## 2. Variables and Collections