core, plugins: host.getClient now raise an exception instead of returning None when no profile is found, plugins have been adapted consequently and a bit cleaned

src/plugins/plugin_misc_radiocol.py

@@ -99,9 +99,6 @@ class Radiocol(object):
         #     be streamed to the backend using XMPP file copy
         #     Here we cheat because we know we are on the same host, and we don't
         #     check data. Referee will have to parse the song himself to check it
-        client = self.host.getClient(profile)
-        if not client:
-            raise exceptions.NotConnectedProfileError(_("Can't access profile's data"))
         try:
             if song_path.lower().endswith('.mp3'):
                 actual_song = MP3(song_path)