BSC: Do not access unbound BTS objects

BTS[1] in function f_start_handler() is not always populated.

- Check BTS[1] before accessing it.

Change-Id: I37fdf7e6ef521677613f4eadc6f1ea236c04ce8e
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index cccec49..796aea3 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -1277,8 +1277,10 @@
 	connect(vc_conn:MGCP_PROC, vc_MGCP:MGCP_PROC);
 	connect(vc_conn:RSL, bts[0].rsl.vc_RSL:CLIENT_PT);
 	connect(vc_conn:RSL_PROC, bts[0].rsl.vc_RSL:RSL_PROC);
-	connect(vc_conn:RSL1, bts[1].rsl.vc_RSL:CLIENT_PT);
-	connect(vc_conn:RSL1_PROC, bts[1].rsl.vc_RSL:RSL_PROC);
+	if (isbound(bts[1])) {
+		connect(vc_conn:RSL1, bts[1].rsl.vc_RSL:CLIENT_PT);
+		connect(vc_conn:RSL1_PROC, bts[1].rsl.vc_RSL:RSL_PROC);
+	}
 	connect(vc_conn:BSSAP, g_bssap.vc_BSSMAP:CLIENT);
 	connect(vc_conn:MGCP, vc_MGCP:MGCP_CLIENT);
 	vc_conn.start(derefers(fn)(id));