patch 9.0.1513: text scrolls unnecessarily when splitting

Problem:    Text scrolls unnecessarily when splitting and 'splitkeep' is not
            "cursor".
Solution:   Avoid resetting w_skipcol. (Luuk van Baal, closes #12334)
diff --git a/src/version.c b/src/version.c
index 08f213a..2665b03 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1513,
+/**/
     1512,
 /**/
     1511,