Add missing return statement

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/webrtc/call.ts

@@ -982,6 +982,7 @@ export class MatrixCall extends EventEmitter {
         }
         this.localUsermediaFeed?.setAudioMuted(muted);
         this.updateMuteStatus();
+        return this.isMicrophoneMuted();
     }
 
     /**