TT#156900 enable single-port use with rtcp-mux=demux/accept

This enables the same behaviour towards the offerer when rtcp-mux=demux
or =accept is used, as we have towards the answerer when
rtcp-mux=require is used.

Change-Id: I56a1cea84efce0c2db1b58c500629d0e54d582f4
(cherry picked from commit 72a2710f63)

daemon/call.c

@@ -2772,7 +2772,8 @@ int monologue_offer_answer(struct call_monologue *dialogue[2], GQueue *streams,
 
 		num_ports_this = proto_num_ports(sp->num_ports, media, flags,
 				flags && flags->rtcp_mux_require ? true : false);
-		num_ports_other = proto_num_ports(sp->num_ports, other_media, flags, false);
+		num_ports_other = proto_num_ports(sp->num_ports, other_media, flags,
+				flags && (flags->rtcp_mux_demux || flags->rtcp_mux_accept) ? true : false);
 
 		/* local interface selection */
 		__init_interface(media, &sp->direction[1], num_ports_this);