Change the order of the indicator implementations fallback

[pacho2]

Currently trayicon plugin will try to load old libappindicator implementation and, if not found, fallback to the new one:

    gi.require_version('AppIndicator3', '0.1')
    from gi.repository import AppIndicator3 as appindicator
except:
    #fall back to Ayatana
    gi.require_version('AyatanaAppIndicator3', '0.1')
    from gi.repository import AyatanaAppIndicator3 as appindicator

the problem is that, during the transition, it is common to have both installed (as they can be installed at the same time) and, then, it will keep using the old (unmaintained) version over the new one.

I would then reverse the logic to fallback to the old implementation if ayatana one is not present

Thanks a lot

[AdamPS]

Great it seems that you know what the fix is. If you could create a pull request and test it works for you then we can merge it.