osmotrx: Make sure remote process stops after ssh session is closed

First of all, it was found that vty allocation must be forced (-t -t)
during ssh session creation to make sure SIGHUP is forwarded when
session is closed.

Second, since osmo-trx ignores SIGHUP (osmo_init_ignore_signals()), we
must add a wrapper script which converts received SIGHUP into a SIGINT
to stop osmo-trx.

Change-Id: Ic334a54b1a1827d74fe0b453ac32bb77b8616147
3 files changed