Fail on a2j start when hw port is busy

[https://www.google.com/accounts/o8/id?id=aitoawlo7jxrmmcwk_j8rbbccceobqxj28wgmdy]

If a alsa/raw port is already in use, when ladi tries to start a2j -e a failure notification is displayed, ladishd crashes and a new studio is created and started.

Note that starting a2j from command line works fine, does not report errors and simply ignores (does not bridge) the busy port.

Test case: Ardour started in session using alsa/raw port to access BCF2000 control surface. Ardour must be started before a2j or it cannot get the port. Starting a2j after ardour works in a manual session but not in gladish. Setting a2j as an app in gladish with command "sleep 10 && a2j -e" should work, but instead causes ladishd to crash.

[http://nedko.arnaudov.name/]

 https://gna.org/support/?2597

[http://nedko.arnaudov.name/]

Please provide a backtrace of the crashed daemon