patch 8.2.4577: message test is flaky

Problem:    Message test is flaky. (Elimar Riesebieter)
Solution:   Trigger the autocommand event only after startup is finished.
diff --git a/src/version.c b/src/version.c
index c447509..ba0058b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4577,
+/**/
     4576,
 /**/
     4575,