epdg: Introduce test TC_s2b_CreateSession_rejected

Related: OS#6371
Change-Id: Ide1df9e359b12094f82e54a7824c83f515aedcc3
diff --git a/mme/MME_Tests.ttcn b/mme/MME_Tests.ttcn
index aa23a84..1cacbd9 100644
--- a/mme/MME_Tests.ttcn
+++ b/mme/MME_Tests.ttcn
@@ -831,6 +831,7 @@
 
 		GTP2.send(ts_GTP2C_CreateSessionResp(g_pars.ue_pars.s11_teic_remote,
 						     rx_msg.sequenceNumber,
+						     Request_accepted,
 						     { s11_fteid_c_ie, s5c_fteid_c_ie },
 						     paa, { ts_GTP2C_BcGrouped(bctx_ies) } ));
 		setverdict(pass);