rtpengine: pass the media-address as we get it

Thanks go to @wangduanduan for reporting it in #2692

(cherry picked from commit 7411e62)

modules/rtpengine/rtpengine.c

@@ -1790,11 +1790,7 @@ static int parse_flags(struct ng_flags_parse *ng_flags, struct sip_msg *msg,
 					break;
 				continue;
 			case 13:
-				if (str_eq(&key, "media-address")) {
-					err = "missing value";
-					if (!val.s)
-						goto error;
-				} else if (str_eq(&key, "received-from")) {
+				if (str_eq(&key, "received-from")) {
 					if (val.s)
 						ng_flags->received_from = val;
 				} else