hnbgw: wait longer for PFCP Assoc

Since I introduced stricter timeouts on PFCP messages in
    hnbgw: add f_pfcp_expect()
    commit 6bbfe057afe6f23e2f325789a3dcac81065ab952
    Change-Id I2117475b695d486b1204d61e5bb21120a6187354
the HNBGW tests with PFCP support fail often:

The Assoc Setup resending timeout (X26) is configured to 5 seconds, and
the timeout to wait for this is also 5 seconds. Every once in a while
they happen to miss, causing a test failure.

Increase the initial Assoc Setup Req timeout to 15 seconds to avoid
sporadic failures.

Change-Id: I4b9af224e2346a4735f3d4e01b234acf56c5f3ff
diff --git a/hnbgw/HNBGW_Tests.ttcn b/hnbgw/HNBGW_Tests.ttcn
index 1c0b121..e9693fe 100644
--- a/hnbgw/HNBGW_Tests.ttcn
+++ b/hnbgw/HNBGW_Tests.ttcn
@@ -1292,10 +1292,10 @@
 	}
 }
 
-private function f_pfcp_expect(template (present) PDU_PFCP exp_rx) runs on ConnHdlr return PDU_PFCP
+private function f_pfcp_expect(template (present) PDU_PFCP exp_rx, float wait_time := 5.0) runs on ConnHdlr return PDU_PFCP
 {
 	var PDU_PFCP rx;
-	timer T := 5.0;
+	timer T := wait_time;
 	T.start;
 	alt {
 	[] PFCP.receive(exp_rx) -> value rx {
@@ -1325,7 +1325,7 @@
 	var PDU_PFCP m;
 	var Node_ID upf_node_id := valueof(ts_PFCP_Node_ID_fqdn("\07osmocom\03org"));
 
-	m := f_pfcp_expect(tr_PFCP_Assoc_Setup_Req())
+	m := f_pfcp_expect(tr_PFCP_Assoc_Setup_Req(), wait_time := 15.0);
 	PFCP.send(ts_PFCP_Assoc_Setup_Resp(m.sequence_number, upf_node_id,
 					   ts_PFCP_Cause(REQUEST_ACCEPTED), 1234));