sgsn: f_pdp_ctx_deact_mt: force teardown to avoid sgsn ignoring msg

According to
"""
If a GSN receives a Delete PDP context without a Teardown In
dicator or with a Teardown Indicator with value set to
"0" and only that PDP context is active for a PDN connection, then the
GSN shall ignore the message.
"""

Change-Id: Id5d4774d719685631e4b467dff833ae886c90145
diff --git a/sgsn/SGSN_Tests.ttcn b/sgsn/SGSN_Tests.ttcn
index 017c724..cfe2d3f 100644
--- a/sgsn/SGSN_Tests.ttcn
+++ b/sgsn/SGSN_Tests.ttcn
@@ -948,7 +948,7 @@
 	var GtpPeer peer := valueof(ts_GtpPeerC(apars.sgsn_ip_c));
 
 	BSSGP.clear;
-	GTP.send(ts_GTPC_DeletePDP(peer, seq_nr, apars.sgsn_tei_c, apars.nsapi, omit));
+	GTP.send(ts_GTPC_DeletePDP(peer, seq_nr, apars.sgsn_tei_c, apars.nsapi, '1'B));
 
 	interleave {
 	[] BSSGP.receive(tr_BD_L3_MT(tr_SM_DEACT_PDP_REQ_MT(apars.tid, ?))) {