OJS 2.4 behind reverse proxy: links in generated mails contain internal port

Describe the issue or problem
I’m trying to enhanced the security for an OJS 2.4 instance (upgrade in the works) by placing it behind a nginx reverse proxy. In my setup OJS via Apache webserver runs locally on port 8443 and the reverse proxy is listening on port 443, both on the same machine.

The http(s) part works fine so far but now I’ve stumbled over the problem that links in mails generated by OJS all include the ‘private port’. Is there a way to configure OJS link generation to omit this port?