osmux: Unify rtp_conn osmux type into a single type

There's no need to separate between BSS and CN side nowadays, the
different types are used nowehere. This separation dates from
osmo-bsc-nat code days.

Change-Id: I65effeddf033eb1955553e8d659c593b4e67f7bc
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index 711ca31..79fbc53 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -150,8 +150,7 @@
 
 	switch (conn->type) {
 	case MGCP_RTP_DEFAULT:
-	case MGCP_OSMUX_BSC:
-	case MGCP_OSMUX_BSC_NAT:
+	case MGCP_RTP_OSMUX:
 	case MGCP_RTP_IUUP:
 		break;
 	default: