patch 8.0.1280: Python None cannot be converted to a Vim type

Problem:    Python None cannot be converted to a Vim type.
Solution:   Convert it to v:none. (Ken Takata)

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1280,
 /**/
     1279,
 /**/