Configure each osmo-* program to send GSMTAP log output to the IP of the
docker container, which runs the testsuite (and therefore runs tcpdump).
Related: https://lists.osmocom.org/pipermail/openbsc/2019-June/012946.html
Change-Id: I99e74f6ffb5b7d566cec35995bf067df414968d8
Some tests require GPRS features not yet present in trxcon, so we have
to fall back using virtphy.
Change-Id: I2f17f03194a4dfa0abca51b0d3e22b3934d08a9a