asterisk: SIP UA: Fix seq_nr transmitting ACK for MO call

RFC 3261 17.1.1.3:
"The CSeq header field in the ACK MUST contain the same value for
the sequence number as was present in the original request"

Change-Id: I3d584d234b11ef9d21f203fbf18d63a5602775f0
---
M asterisk/SIP_ConnectionHandler.ttcn
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/asterisk/SIP_ConnectionHandler.ttcn b/asterisk/SIP_ConnectionHandler.ttcn
index 696be8a..52290fd 100644
--- a/asterisk/SIP_ConnectionHandler.ttcn
+++ b/asterisk/SIP_ConnectionHandler.ttcn
@@ -482,7 +482,6 @@
 	g_pars.cp.to_addr := g_rx_sip_resp.msgHeader.toField;
 
 	/* Transmit ACK */
-	g_pars.cp.sip_seq_nr := g_pars.cp.sip_seq_nr + 1;
 	req := ts_SIP_ACK(g_pars.cp.sip_call_id,
 			  g_pars.cp.from_addr,
 			  g_pars.cp.to_addr,

