ttcn3-bts-test: do not start osmo-bts-virtual / virtphy containers
We cannot execute the virtphy based testcases due to the limitations of Docker (see https://github.com/moby/libnetwork/issues/2397). The function starting the testsuite was already commented out, but not the lines starting containers with osmo-bts-virtual and virtphy.
To put it simple, we start and immediately terminate those containers. And since recently (Feb 1st), we started seeing socket creation errors in both containers, causing jenkins.sh to abort early. It's yet unclear what's the cause of those socket errors, but regardless of that we should still be running other pending testcases.
