Add a missing line continuation character.

Objects/unicodeobject.c

@@ -5987,7 +5987,7 @@ PyDoc_STRVAR(split__doc__,
 \n\
 Return a list of the words in S, using sep as the\n\
 delimiter string.  If maxsplit is given, at most maxsplit\n\
-splits are done. If sep is not specified or is None,
+splits are done. If sep is not specified or is None,\n\
 any whitespace string is a separator.");
 
 static PyObject*