Cleanup event on exit.

* Cleanup CLI commands on exit.

(issue ASTERISK-20649)
Reported by: Corey Farrell
Patches:
      event_shutdown-10-only.patch (license #5909) patch uploaded by Corey Farrell
      event_shutdown-1_8-11-trunk.patch (license #5909) patch uploaded by Corey Farrell
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Merged revisions 377708 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 377709 from http://svn.asterisk.org/svn/asterisk/branches/10
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Merged revisions 377710 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@377711 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/event.c

@@ -1817,6 +1817,8 @@ static void event_shutdown(void)
 	struct ast_event_sub *sub;
 	int i;
 
+	ast_cli_unregister_multiple(event_cli, ARRAY_LEN(event_cli));
+
 	if (event_dispatcher) {
 		event_dispatcher = ast_taskprocessor_unreference(event_dispatcher);
 	}