fix a bug where the client blocks the finder(or explorer in windows) by dropping a file
fix a bug where the client blocks the finder(or explorer in windows) by dropping a file

cloudcopy/client,ggkitsas/seafile-client,lucius-feng/seafile-client,wgaalves/seafile-client,losingle/seafile-client,haiwen/seafile-client,lucius-feng/seafile-client,cloudcopy/client,ggkitsas/seafile-client,cloudcopy/client,losingle/seafile-client,lucius-feng/seafile-client,haiwen/seafile-client,losingle/seafile-client,daodaoliang/seafile-client,haiwen/seafile-client,wgaalves/seafile-client,daodaoliang/seafile-client,wgaalves/seafile-client,ggkitsas/seafile-client,haiwen/seafile-client,lucius-feng/seafile-client,daodaoliang/seafile-client,losingle/seafile-client,daodaoliang/seafile-client,wgaalves/seafile-client,cloudcopy/client,ggkitsas/seafile-client