Fix typo in JabberSend that looked for '2' instead of '@' in recipient argument

The summary says about all there is to say.

(closes issue ASTERISK-20239)
Reported by: Gregory Porras
........

Merged revisions 371518 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@371519 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_xmpp.c

@@ -1748,7 +1748,7 @@ static int xmpp_send_exec(struct ast_channel *chan, const char *data)
 
 	AST_STANDARD_APP_ARGS(args, s);
 
-	if ((args.argc < 3) || ast_strlen_zero(args.message) || !strchr(args.recipient, '2')) {
+	if ((args.argc < 3) || ast_strlen_zero(args.message) || !strchr(args.recipient, '@')) {
 		ast_log(LOG_WARNING, "%s requires arguments (account,jid,message)\n", app_ajisend);
 		return -1;
 	}