Also change the default max width to 500px (instead of 400px).

Change-Id: Idece5aadaf4c4165cc873b4605d2c0f026c89c6e
Reviewed-on: https://gerrit.libreoffice.org/69545
Tested-by: Jenkins
Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>