Bliss+Tmux: no message if beacon is not running
in case beacon is not running
without tmux
$ TANGO_HOST=localhost:20000 bliss --no-tmux
!!! === RuntimeError: Could not find any conductor (check Beacon server and BEACON_HOST environment variable) === !!! ( for more details type cmd 'last_error' )
with tmux
$ TANGO_HOST=localhost:20000 bliss
Starting new tmux session __DEFAULT__...
[exited]
Can we display the error message outside of tmux in case bliss crashes?