Fix DAV stat cache to properly cache 404
Fix DAV stat cache to properly cache 404

404 errors were not properly cached due to catching the wrong
exception. Now catching ClientHttpException and checking the error
code. In case of 404, adjust the stat cache accordingly.

whitekiba/server,michaelletzgus/nextcloud-server,pixelipo/server,nextcloud/server,nextcloud/server,pixelipo/server,Ardinis/server,endsguy/server,pmattern/server,xx621998xx/server,endsguy/server,jbicha/server,pmattern/server,jbicha/server,nextcloud/server,michaelletzgus/nextcloud-server,pixelipo/server,andreas-p/nextcloud-server,xx621998xx/server,pixelipo/server,Ardinis/server,andreas-p/nextcloud-server,whitekiba/server,whitekiba/server,michaelletzgus/nextcloud-server,jbicha/server,jbicha/server,whitekiba/server,endsguy/server,andreas-p/nextcloud-server,whitekiba/server,xx621998xx/server,endsguy/server,pmattern/server,andreas-p/nextcloud-server,xx621998xx/server,pixelipo/server,xx621998xx/server,pmattern/server,Ardinis/server,jbicha/server,nextcloud/server,andreas-p/nextcloud-server,Ardinis/server,michaelletzgus/nextcloud-server,endsguy/server,pmattern/server,Ardinis/server