more robust png fallback
more robust png fallback

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