Add TC_attach_pdp_act_user_deact_mt for GGSN-originated PDP DEACT

Change-Id: I7eb653694f487f8bbf122146300c93be625b0f87
Related: OS#2961
diff --git a/library/GTP_Templates.ttcn b/library/GTP_Templates.ttcn
index ef7e97b..44d9682 100644
--- a/library/GTP_Templates.ttcn
+++ b/library/GTP_Templates.ttcn
@@ -456,12 +456,10 @@
 		ts_IPCP(LCP_Configure_Request, identifier,
 			{ tr_IPCP_PrimaryDns('00000000'O), tr_IPCP_SecondaryDns('00000000'O) });
 
-	function f_teardown_ind_IE(in template BIT1 ind) return template TearDownInd {
-/*
-		if (not isvalue(ind)) {
+	function f_teardown_ind_IE(in template (omit) BIT1 ind) return template (omit) TearDownInd {
+		if (istemplatekind(ind, "omit")) {
 			return omit;
 		}
-*/
 		var TearDownInd ret := {
 			type_gtpc := '13'O,
 			tdInd := valueof(ind),
@@ -470,7 +468,7 @@
 		return ret;
 	}
 
-	template GTPC_PDUs ts_DeletePdpPDU(BIT4 nsapi, template BIT1 teardown_ind) := {
+	template GTPC_PDUs ts_DeletePdpPDU(BIT4 nsapi, template (omit) BIT1 teardown_ind) := {
 		deletePDPContextRequest := {
 			cause := omit,
 			tearDownIndicator := f_teardown_ind_IE(teardown_ind),
@@ -489,7 +487,7 @@
 	}
 
 	template Gtp1cUnitdata ts_GTPC_DeletePDP(GtpPeer peer, uint16_t seq, OCT4 teid,
-						 BIT4 nsapi, template BIT1 teardown_ind) := {
+						 BIT4 nsapi, template (omit) BIT1 teardown_ind) := {
 		peer := peer,
 		gtpc := ts_GTP1C_PDU(deletePDPContextRequest, teid,
 					valueof(ts_DeletePdpPDU(nsapi, teardown_ind)), seq)