msc: Make TC_lu_clear_request tolerant to double ClearCommand from MSC

See https://osmocom.org/issues/2862

Change-Id: Ic266151038dc29220ec62279d16fcd181836bb42
diff --git a/msc_tests/MSC_Tests.ttcn b/msc_tests/MSC_Tests.ttcn
index c8ac429..d0000d8 100644
--- a/msc_tests/MSC_Tests.ttcn
+++ b/msc_tests/MSC_Tests.ttcn
@@ -624,7 +624,11 @@
 	BSSAP.send(ts_BSSMAP_ClearRequest(0));
 	BSSAP.receive(tr_BSSMAP_ClearCommand);
 	BSSAP.send(ts_BSSMAP_ClearComplete);
-	BSSAP.receive(BSSAP_Conn_Prim:MSC_CONN_PRIM_DISC_IND);
+	alt {
+	/* See https://osmocom.org/issues/2862 */
+	[] BSSAP.receive(tr_BSSMAP_ClearCommand) { repeat; }
+	[] BSSAP.receive(BSSAP_Conn_Prim:MSC_CONN_PRIM_DISC_IND) {}
+	}
 	setverdict(pass);
 }
 testcase TC_lu_clear_request() runs on MTC_CT {