Fix slow update of "Join/leave call" button

The button is updated when the model changes, but the model was not
being synced when the user joined or left a call, so it only changed
when it was synced for any other reason.

Fixes #473

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

js/webrtc.js

@@ -661,10 +661,16 @@ var spreedPeerConnectionTable = [];
 		});
 
 		OCA.SpreedMe.webrtc.on('joinedCall', function() {
+			OCA.SpreedMe.app.syncRooms();
+
 			$('#app-content').removeClass('icon-loading');
 			$('.videoView').removeClass('hidden');
 		});
 
+		OCA.SpreedMe.webrtc.on('leftCall', function() {
+			OCA.SpreedMe.app.syncRooms();
+		});
+
 		OCA.SpreedMe.webrtc.on('channelOpen', function(channel) {
 			console.log('%s datachannel is open', channel.label);
 		});