Support custom port for proxy host domain name

[Hadatko]

Is your feature request related to a problem? Please describe.

Press Add Proxy Host i have option to add domain names. Added domain names then appear in Proxy Hosts table where on first column appear domain names which can be then clicked and you are forwarded to the page. For example when i want use foo.bar.eu on different port i can add domain name 'foo.bar.eu:11111'. When i click then in Proxy Hosts table on my link i am correctly forwarded to foo.bar.eu:11111, but when i want create SSL certificate using dns the the whole address is provided to certbot but the port in domain name is causing issue. I am curious if you can add support for custom port so i would be able generate certificate for foo.bar.eu but in table i would be able to click on foo.bar.eu:11111 to access that web page.

Describe the solution you'd like

Somehow be able to modify link for domain to access web on different port. So i would be able to generate certificate for foo.bar.eu but url for page would be foo.bar.eu:11111

Describe alternatives you've considered

Additional context

[Hadatko]

proxy hosts table