S1AP_Emulation: fix f_s1ap_id_table_del

When we search for the entry that we want to delete, we use the
ENB_UE_S1AP_ID as a search key, but we compare it against
mme_ue_s1ap_id. This is not correct, it should be compared against
enb_ue_s1ap_id

Change-Id: I8528af4e3fda0bc97f8b14785097434a6163bcc4
Related: OS#5760
diff --git a/library/S1AP_Emulation.ttcn b/library/S1AP_Emulation.ttcn
index 0ecbd99..0671d08 100644
--- a/library/S1AP_Emulation.ttcn
+++ b/library/S1AP_Emulation.ttcn
@@ -253,7 +253,7 @@
 	var integer i;
 	for (i := 0; i < sizeof(S1apAssociationTable); i := i+1) {
 		if (S1apAssociationTable[i].comp_ref == comp_ref and
-		    S1apAssociationTable[i].mme_ue_s1ap_id == enb_id) {
+		    S1apAssociationTable[i].enb_ue_s1ap_id == enb_id) {
 			S1apAssociationTable[i].enb_ue_s1ap_id := omit;
 			S1apAssociationTable[i].mme_ue_s1ap_id := omit;
 			S1apAssociationTable[i].comp_ref := null;