fix bug pop_back
fix bug pop_back

ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core,ONLYOFFICE/core