Fix MGCP *67 to automatically reset callerid (bug #3940)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5382 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_mgcp.c

@@ -1047,6 +1047,7 @@ static int mgcp_hangup(struct ast_channel *ast)
 	/* SC: Decrement use count */
 
 	if ((p->hookstate == MGCP_ONHOOK) && (!sub->next->rtp)) {
+		p->hidecallerid = 0;
 		if (has_voicemail(p)) {
 			if (mgcpdebug) {
 				ast_verbose(VERBOSE_PREFIX_3 "MGCP mgcp_hangup(%s) on %s@%s set vmwi(+)\n",