msc/BSC_ConnHdlr: f_mt_call: unregister IMSI

Fix the missing call to f_ran_unregister_imsi when running f_mt_call.

This is in preparation for calling f_mt_call multiple times during one
test, to test various CSD bearer services. Without this patch, it will
result in a "No space left in ImsiTable" error.

I've also considered adding it to f_call_hangup instead, but this gets
called by f_mo_call (mo instead of mt) as well, which does not run
f_ran_register_imsi.

Related: OS#4394
Change-Id: Ie9b180b95348d7e84650c14a331c5091a1e67d1f
---
M msc/BSC_ConnectionHandler.ttcn
1 file changed, 23 insertions(+), 0 deletions(-)

diff --git a/msc/BSC_ConnectionHandler.ttcn b/msc/BSC_ConnectionHandler.ttcn
index 8c9f63f..76702d4 100644
--- a/msc/BSC_ConnectionHandler.ttcn
+++ b/msc/BSC_ConnectionHandler.ttcn
@@ -1851,6 +1851,9 @@
 	log("Hangup");
 	f_call_hangup(cpars, true);
 
+	/* Unregister the IMSI that was registered in f_mt_call_establish */
+	f_ran_unregister_imsi(g_pars.imsi);
+
 	setverdict(pass);
 }
 

