patch 9.0.1036: undo misbehaves when writing from an insert mode mapping

Problem:    Undo misbehaves when writing from an insert mode mapping.
Solution:   Sync undo when writing. (closes #11674)
diff --git a/src/version.c b/src/version.c
index 7ae34f4..9c162fb 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1036,
+/**/
     1035,
 /**/
     1034,