Merge pull request #625 from ai0376/master

fix break loop

Author: daijh

source/agent/video/videoMixer/VideoMixer.cpp

@@ -216,6 +216,7 @@ void VideoMixer::closeAll()
     auto it = m_inputs.begin();
     while (it != m_inputs.end()) {
         m_frameMixer->removeInput(*it);
+        it++;
     }
     m_inputs.clear();
 
@@ -225,6 +226,7 @@ void VideoMixer::closeAll()
         while (it != m_outputs.end()) {
             int32_t index = it->second;
             m_frameMixer->removeOutput(index);
+            it++;
         }
         boost::upgrade_to_unique_lock<boost::shared_mutex> outputLock1(outputLock);
         m_outputs.clear();