l1fwd-proxy: Bind to the bts VTY port to block another process
l1fwd-proxy: Bind to the bts VTY port to block another process

Today we had the problem that multiple l1fwd-proxy instances ran
at the same time and not everything working all the time (some
packets were sent to a different host).

Another approach is to use flock on the message queues. This appears
to work fine as well.

telenoobie/osmo-bts,telenoobie/osmo-bts,osmocom/osmo-bts,osmocom/osmo-bts,geosphere/osmo-bts,osmocom/osmo-bts,geosphere/osmo-bts,telenoobie/osmo-bts,geosphere/osmo-bts,telenoobie/osmo-bts,geosphere/osmo-bts