Add fix for custom ports

[Fmstrat]

Currently if you have a setup like this in Nextcloud and OnlyOffice (such as with Docker):

ONLYOFFICE Docs address: https://onlyoffice.mydomain.com:1111/
ONLYOFFICE Docs address for internal requests from the server: http://onlyoffice/
Server address for internal requests from ONLYOFFICE Docs: http://nextcloud/

You cannot save documents. This is because OnlyOffice sends a request to Nextcloud with a JSON body that contains https://onlyoffice.mydomain.com/ instead of https://onlyoffice.mydomain.com:1111/. This might be why there are a number of reports out there of the cannot save files still floating around.

I'm not sure if this is the best way to fix this, but basically this forces a replacement on the URL without a port to cover off on the scenario.

[CLAassistant]

All committers have signed the CLA.