[pdf] Fix the problem with rendering images with soft mask
[pdf] Fix the problem with rendering images with soft mask

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