bts: Sleep for some time after RSL is up before using it

This is a work-around for an OsmoBSC bug, see OS#3000

Change-Id: I9a552984a895b08d3f517bdc5844b810eb57700f
Related: OS#3000
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index d3bdd62..bf7e839 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -136,6 +136,7 @@
 function f_init(charstring id := "BTS-Test") runs on test_CT {
 	f_init_rsl(id);
 	RSL_CCHAN.receive(ASP_IPA_Event:{up_down := ASP_IPA_EVENT_UP});
+	f_sleep(0.5);	/* workaround for OS#3000 */
 
 	/* Send SI3 to the BTS, it is needed for various computations */
 	var GsmRrMessage si3 := valueof(ts_SI3_default);