gb_proxy: Broadcast SGSN-INVOKE-TRACE and OVERLOAD

Both BSSGP messages appear from the SGSN in downlink on BVCI=0.

We must send a copy of this message to each of the BSS side NSEs.

Change-Id: Ia19791b143989eb1490f461d88b9edbd8e3b82be
Closes: OS#4875
1 file changed