also show message for empty display name if change of it isn't allowed
also show message for empty display name if change of it isn't allowed

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