ns/gbproxy/sgsn: Update configs to use logging level lnssignal'

In libosmocore I34b8fde2955ecc010d1dcd9512e1bba9211e2c0d we introduced
a new log subsystem; enabel it in the related configs here

Change-Id: Ie3d178e68aa81d5636c87940074cb6582ac2f131
5 files changed