fix other warning

Author: AndreaCrotti

snippets/python-mode/function_docstring

@@ -2,8 +2,8 @@
 # name: function_docstring
 # key: fd
 # group: definitions
-# NOTE Use minimum indentation, because Emacs 25+ doesn't dedent docstrings.
 # --
+# NOTE: Use minimum indentation, because Emacs 25+ doesn't dedent docstrings.
 def ${1:name}($2):
  \"\"\"$3
  ${2:$(python-args-to-docstring)}