Fix that we are currently building osmo-gbproxy against an old libosmocore in ttcn3-gbproxy-test-fr. This is currently causing the job to fail with:
/usr/bin/ld: gb_proxy_vty.o: in function `log_set_bvc_filter': /tmp/osmo-gbproxy/src/gb_proxy_vty.c:477: undefined reference to `log_set_filter' /usr/bin/ld: /tmp/osmo-gbproxy/src/gb_proxy_vty.c:478: undefined reference to `log_set_filter_data' collect2: error: ld returned 1 exit status
