fixed cspot crash when switching with LMS

components/spotify/cspot/bell/include/Queue.h

@@ -103,6 +103,8 @@ namespace bell
                 //delete m_queue.front();
                 m_queue.pop();
             }
+            lk.unlock();
+            m_cv.notify_one();
         }
         /// <summary> Check queue in forced exit state. </summary>
         bool isExit() const