bsc: Introduce Osmux infra and one test for osmo-bsc

Test verifies once osmux is enabled in osmo-bsc, BSSMAP RESET (ACK)
contains Osmux Support IE and that it correctly handles BSSMAP ASsign
Req with Osmux CID.

Related: OS#2551
Depends: osmo-bsc 6de754cdde5319af3059d8fc6abf85037ec7eacc
Depends: titan.ProtocolModules.BSSMAP Iaf1e137269c0da20b2c96fd104b57edf336693af
Change-Id: If69c716dc06d61d810c32d1720a237c7535baca8
diff --git a/bsc-nat/MSC_ConnectionHandler.ttcn b/bsc-nat/MSC_ConnectionHandler.ttcn
index 8635a29..36fdf85 100644
--- a/bsc-nat/MSC_ConnectionHandler.ttcn
+++ b/bsc-nat/MSC_ConnectionHandler.ttcn
@@ -60,6 +60,7 @@
 	decode_dtap := false,
 	role_ms := false,
 	protocol := RAN_PROTOCOL_BSSAP,
+	use_osmux := false,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }