updated for version 7.4.491

Problem:    When winrestview() has a negative "topline" value there are
            display errors.
Solution:   Correct a negative value to 1. (Hirohito Higashi)

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    491,
 /**/
     490,
 /**/