Update third_party-roundcube.en.md

[dudemcbacon]

The ROUNDCUBEMAIL_REQUEST_PATH env var is required otherwise roundcube will not forward POST requests to the correct path.

[CodeShellDev]

There were previously issues with ROUNDCUBEMAIL_REQUEST_PATH: /rc/ not working (this is why we have to use nginx, traefik for example does not work)
not sure if these issues were fixed upstream.

[majoragee]

I just setup Roundcube for the first time and this env var was indeed required. Otherwise, the login was sending me to the active SOGo session.

[CodeShellDev]

I just setup Roundcube for the first time and this env var was indeed required. Otherwise, the login was sending me to the active SOGo session.

Cool, I guess they may have fixed the bug, or it was just a problem with my setup (using traefik)!

[MAGICCC]

@CodeShellDev can you recheck this with traefik maybe?

[CodeShellDev]

Had tried it out a few weeks ago, and it seemed to work with the environment variable!