patch 8.2.2420: too many problems with using all autocommand events

Problem:    Too many problems with using all autocommand events.
Solution:   Disallow defining an autocommand for all events.
diff --git a/src/version.c b/src/version.c
index 160b538..3d0613c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2420,
+/**/
     2419,
 /**/
     2418,