patch 8.2.0649: undo problem whn an InsertLeave autocommand resets undo

Problem:    Undo problem whn an InsertLeave autocommand resets undo. (Kutsan
            Kaplan)
Solution:   Do not create a new undo block when leaving Insert mode.
diff --git a/src/version.c b/src/version.c
index a9a2e29..fa91a2b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    649,
+/**/
     648,
 /**/
     647,