sgsn: rework TC_attach_closed_add_vty to be executed in a single BSSGP_ConnHldr

When stopping and starting BSSGP_ConnHdlr multiple times, there
are Port connecting problems. Using a single iteration of
BSSGP_ConnHldr.start() works around this problem.

Change-Id: I8e5ae832f3908a172b9beb6d936074b806e0c799
1 file changed