fsplugin: fix codesign issue on OS X 10.10.4
fsplugin: fix codesign issue on OS X 10.10.4

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