patch 8.0.0490: vertical split makes 'winfixwidth' window smaller

Problem:    Splitting a 'winfixwidth' window vertically makes it one column
            smaller. (Dominique Pelle)
Solution:   Add one to the width for the separator.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    490,
 /**/
     489,
 /**/