Port DAV groupMemberSet fix to master #4458
Port DAV groupMemberSet fix to master #4458

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