hlr: Fix test of UL+ISD state machine

Don't exit too early: After sending ISD.resp we still need to wait
for the UL.res from the HLR before continuing processing.

Change-Id: Iab42a397cbca83b86fc8a6b26ae2d66abb81c187
diff --git a/hlr/HLR_Tests.ttcn b/hlr/HLR_Tests.ttcn
index bb417a5..7efc2b7 100644
--- a/hlr/HLR_Tests.ttcn
+++ b/hlr/HLR_Tests.ttcn
@@ -299,6 +299,7 @@
 	[not exp_fail and not isd_done] GSUP.receive(tr_GSUP_ISD_REQ(imsi, msisdn)) -> value ret {
 		GSUP.send(ts_GSUP_ISD_RES(imsi));
 		isd_done := true;
+		repeat;
 		}
 	[not exp_fail and isd_done] GSUP.receive(tr_GSUP_UL_RES(imsi)) -> value ret {
 		setverdict(pass);