Bug #40704 main.events_restart fails sporadically in pushbuild: "server has gone away"

mysql-test/include/wait_until_disconnected.inc:
  Allow 2013 as an expected error code

mysql-test/include/wait_until_disconnected.inc

@@ -7,7 +7,7 @@ let $counter= 500;
 let $mysql_errno= 0;
 while (!$mysql_errno)
 {
-  --error 0,1053,2002,2006
+  --error 0,1053,2002,2006,2013
   show status;
 
   dec $counter;