chan_pjsip: fix music on hold continues after INVITE with replaces

In a three party scenario with INVITE with replaces, we need to
unhold the call, otherwise one party continues to get music on
hold, and the call is not properly bridged between them.

ASTERISK-30428

Change-Id: I5675df11e739be5226b328f8828d4b8d81fbefb4

res/res_pjsip_refer.c

@@ -1019,6 +1019,10 @@ static int refer_incoming_invite_request(struct ast_sip_session *session, struct
 	ast_debug(3, "INVITE with Replaces being attempted.  '%s' --> '%s'\n",
 		ast_channel_name(session->channel), ast_channel_name(invite.channel));
 
+	/* Unhold the channel now, as later we are not having access to it anymore */
+	ast_queue_unhold(session->channel);
+	ast_queue_frame(session->channel, &ast_null_frame);
+
 	if (!invite.bridge) {
 		struct ast_channel *chan = session->channel;