Allocating a pseudo-TTY (-t, --tty) fails when 'run' is executed
inside of a Jenkins or cron script. This change fixes
ttcn3-bts-test, which invokes 'run' to fetch the config files.
Change-Id: If22f682be4f004c5bb43e65098079a4f4fe6158d
Fixes: If15461240f3037c142c176fc7da745a1701ae3f8
plus some configuration to make it available at 127.20.0.10 and
fd10:5741:8e20:0000::10, where a sample index.html file can be
downloaded for testing. Also, make container start in "pdn" network,
the external PDN behind the GGSN