avoid $this->cache being null - fixes #13491
avoid $this->cache being null - fixes #13491

pollopolea/core,pixelipo/server,Ardinis/server,bluelml/core,xx621998xx/server,jbicha/server,endsguy/server,michaelletzgus/nextcloud-server,whitekiba/server,pixelipo/server,owncloud/core,endsguy/server,andreas-p/nextcloud-server,michaelletzgus/nextcloud-server,cernbox/core,jbicha/server,andreas-p/nextcloud-server,owncloud/core,sharidas/core,nextcloud/server,pmattern/server,andreas-p/nextcloud-server,pollopolea/core,andreas-p/nextcloud-server,lrytz/core,sharidas/core,endsguy/server,bluelml/core,lrytz/core,xx621998xx/server,cernbox/core,whitekiba/server,pmattern/server,jbicha/server,nextcloud/server,IljaN/core,pollopolea/core,cernbox/core,bluelml/core,pmattern/server,pollopolea/core,sharidas/core,IljaN/core,cernbox/core,endsguy/server,pixelipo/server,Ardinis/server,owncloud/core,lrytz/core,xx621998xx/server,nextcloud/server,cernbox/core,andreas-p/nextcloud-server,jbicha/server,pollopolea/core,pmattern/server,whitekiba/server,owncloud/core,Ardinis/server,Ardinis/server,whitekiba/server,pmattern/server,phil-davis/core,IljaN/core,lrytz/core,lrytz/core,jbicha/server,endsguy/server,sharidas/core,xx621998xx/server,michaelletzgus/nextcloud-server,michaelletzgus/nextcloud-server,pixelipo/server,whitekiba/server,Ardinis/server,IljaN/core,bluelml/core,xx621998xx/server,bluelml/core,IljaN/core,owncloud/core,pixelipo/server,nextcloud/server,sharidas/core