mme: expect EMM Information received after attach

open5gs-mmed transmits it after attach  complete.
Read it so that it's not kept queued in the port and follow-up uses of
the port don't provide unexpected results.

Change-Id: I6f19a18cced7acd2b831c943e8b3a1f462378435
---
M mme/MME_Tests.ttcn
1 file changed, 16 insertions(+), 0 deletions(-)

diff --git a/mme/MME_Tests.ttcn b/mme/MME_Tests.ttcn
index 7f714fc..3d081ba 100644
--- a/mme/MME_Tests.ttcn
+++ b/mme/MME_Tests.ttcn
@@ -634,6 +634,9 @@
 		nas := ts_NAS_ActDefEpsBearCtxAck(int2bit(g_pars.ue_pars.bearer.ebi, 4), '00000000'B, omit);
 		esm_enc := enc_PDU_NAS_EPS(valueof(nas));
 		S1AP.send(ts_NAS_AttachComplete(esm_enc));
+
+		/* Optional from the network: */
+		S1AP.receive(tr_NAS_EMMInformation);
 		}
 	[] S1AP.receive(PDU_NAS_EPS:?) -> value rx_nas {
 		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, log2str("Rx Unexpected NAS PDU msg: ", rx_nas));

