patch 9.0.1603: display wrong if scrolling multiple lines with 'smoothscroll'

Problem:    Display wrong when scrolling multiple lines with 'smoothscroll'
            set.
Solution:   Redraw when w_skipcol changed. (closes #12477, closes #12468)

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1603,
 /**/
     1602,
 /**/