fix(device-selection): pass dispatch so preferred speaker is saved

conference.js

@@ -2137,7 +2137,7 @@ export default {
             UIEvents.AUDIO_OUTPUT_DEVICE_CHANGED,
             audioOutputDeviceId => {
                 sendAnalytics(createDeviceChangedEvent('audio', 'output'));
-                setAudioOutputDeviceId(audioOutputDeviceId)
+                setAudioOutputDeviceId(audioOutputDeviceId, APP.store.dispatch)
                     .then(() => logger.log('changed audio output device'))
                     .catch(err => {
                         logger.warn('Failed to change audio output device. '
@@ -2374,9 +2374,13 @@ export default {
         const videoWasMuted = this.isLocalVideoMuted();
 
         if (typeof newDevices.audiooutput !== 'undefined') {
-            // Just ignore any errors in catch block.
-            promises.push(setAudioOutputDeviceId(newDevices.audiooutput)
-                .catch());
+            const { dispatch } = APP.store;
+            const setAudioOutputPromise
+                = setAudioOutputDeviceId(newDevices.audiooutput, dispatch)
+                    .catch(); // Just ignore any errors in catch block.
+
+
+            promises.push(setAudioOutputPromise);
         }
 
         promises.push(