patch 8.0.1287: temp file used for viminfo may have wrong permissions

Problem:    The temp file used when updating the viminfo file may have the
            wrong permissions if setting the group fails.
Solution:   Check if the group matches and reduce permissions if not.

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1287,
 /**/
     1286,
 /**/