patch 8.1.1419: listener callbacks may be called recursively

Problem:    Listener callbacks may be called recursively.
Solution:   Set "updating_screen" while listener callbacks are invoked.
diff --git a/src/version.c b/src/version.c
index 511b28b..089b44f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1419,
+/**/
     1418,
 /**/
     1417,