patch 9.0.0892: may redraw when not needed

Problem:    May redraw when not needed, causing slow scrolling.
Solution:   Do not redraw when w_skipcol doesn't change.  When w_skipcol
            changes only redraw from the top. (issue #11559)
diff --git a/src/version.c b/src/version.c
index 0423d0d..b526652 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    892,
+/**/
     891,
 /**/
     890,