Make a NOTICE about an invalid channel name more useful.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@406918 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/manager.c

@@ -3369,7 +3369,8 @@ static int action_hangup(struct mansession *s, const struct message *m)
 
 	if (name_or_regex[0] != '/') {
 		if (!(c = ast_channel_get_by_name(name_or_regex))) {
-			ast_log(LOG_NOTICE, "!!!!!!!!!! Can't find channel to hang up!\n");
+			ast_log(LOG_NOTICE, "Request to hangup non-existent channel: %s\n",
+				name_or_regex);
 			astman_send_error(s, m, "No such channel");
 			return 0;
 		}