gbproxy: Change logging settings

Change-Id: Ib153cfdb337ea0d748aa18e2b8eb16db01d79edd
diff --git a/gbproxy/osmo-gbproxy.cfg b/gbproxy/osmo-gbproxy.cfg
index 6f4b1e7..53dc0f2 100644
--- a/gbproxy/osmo-gbproxy.cfg
+++ b/gbproxy/osmo-gbproxy.cfg
@@ -2,6 +2,16 @@
 ! Osmocom Gb Proxy (0.9.0.404-6463) configuration saved from vty
 !!
 !
+log stderr
+ logging filter all 1
+ logging color 1
+ logging print category 1
+ logging print category-hex 0
+ logging timestamp 1
+ logging print file 1
+ logging level lns debug
+ logging level lbssgp debug
+ logging level gprs debug
 line vty
  no login
 !