asterisk: Fix accessing to unset called_contact var in MT call without precondition

Change-Id: I7e7a6010c3b217c163945027d5c341bcb820c251
---
M asterisk/IMS_ConnectionHandler.ttcn
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/asterisk/IMS_ConnectionHandler.ttcn b/asterisk/IMS_ConnectionHandler.ttcn
index 14e6cd4..3e4e3e9 100644
--- a/asterisk/IMS_ConnectionHandler.ttcn
+++ b/asterisk/IMS_ConnectionHandler.ttcn
@@ -1319,20 +1319,20 @@
 			sip_seq_nr, "INVITE");
 	d_ringing := activate(as_SIP_ignore_resp(exp));
 
-	called_contact := g_rx_sip_resp.msgHeader.contact;
-
 	/* Wait for 200 OK (INVITE) answer */
 	exp := tr_SIP_Response(
 			g_pars.subscr.cp.sip_call_id,
 			from_addr_exp,
 			to_addr_exp,
 			f_tr_Via_response(via),
-			called_contact,
+			?,
 			"INVITE", 200,
 			sip_seq_nr, "OK",
 			body := *);
 	as_SIP_expect_resp(exp, fail_others := false);
 
+	called_contact := g_rx_sip_resp.msgHeader.contact;
+
 	deactivate(d_trying);
 	deactivate(d_ringing);
 

