bsc: Add module param to disable osmux (fix bsc-latest jenkins job)

ttcn3-bsc-test-latest currently fails on most tests because it tries to
use "osmux off" VTY param and only current osmo-bsc master supports it.

Change-Id: I61e4c59b2926f3f70cb6d0190a8683861e54179a
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 85260bc..a84277f 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -122,6 +122,11 @@
 		sio := '83'O,
 		rctx := 0
 	};
+
+	/* Whether to enable osmux tests. Can be dropped completely and enable
+	   unconditionally once new version of osmo-bsc is released (current
+	   version: 1.4.1) */
+	boolean mp_enable_osmux_test := true;
 }
 
 private function f_gen_test_hdlr_pars() return TestHdlrParams {
@@ -335,7 +340,9 @@
 	activate(as_Tguard());
 
 	f_init_vty("VirtMSC");
-	f_vty_allow_osmux(allow_osmux);
+	if (mp_enable_osmux_test) {
+		f_vty_allow_osmux(allow_osmux);
+	}
 
 	/* Call a function of our 'parent component' RAN_Adapter_CT to start the
 	 * MSC-side BSSAP emulation */
@@ -4061,7 +4068,9 @@
 	execute( TC_assignment_codec_req_hr_fr() );
 	execute( TC_assignment_codec_req_fr_hr() );
 
-	execute( TC_assignment_osmux() );
+	if (mp_enable_osmux_test) {
+		execute( TC_assignment_osmux() );
+	}
 
 	/* RLL Establish Indication on inactive DCHAN / SAPI */
 	execute( TC_rll_est_ind_inact_lchan() );