fix calculation of expiration date if there is a default expiration date set (but not forced) and the user does not want the link to expire.
fix calculation of expiration date if there is a default expiration date set (but not forced) and the user does not want the link to expire.

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