sgsn: TC_attach_check_complete_resend: Expect LU sent to HLR

SGSN is expected to submit an LU after initial GMM Auth

Change-Id: Ie2e8f5b9740c7429f5f0bf28e35707a61f23b565
diff --git a/sgsn/SGSN_Tests.ttcn b/sgsn/SGSN_Tests.ttcn
index 6de9987..182cbd2 100644
--- a/sgsn/SGSN_Tests.ttcn
+++ b/sgsn/SGSN_Tests.ttcn
@@ -2325,6 +2325,8 @@
 
 	f_send_l3(ts_GMM_ATTACH_REQ(f_mi_get_lv(), f_random_RAI(), true, false, omit, omit));
 	f_gmm_auth();
+	/* Expect SGSN to perform LU with HLR */
+	f_gmm_gsup_lu_isd();
 
 	timer T := 10.0;
 	T.start;