osmo-gbproxy: Change config file to comply with change in upstream
In osmo-sgsn Change-Id Id67592aa7712e5e04e7264b2fb8f26d57eb7e69e we
have changed the config file syntax and must adjust here accordingly.
Change-Id: I8770baac2298ee9a71d7428ea30600751783b4f9
Depends: osmo-sgsn Id67592aa7712e5e04e7264b2fb8f26d57eb7e69e
