Add support for SSL upstream frigate servers in frigate_proxy.

[antonjs]

• Adds protocol to the server URI to allow specifying an http or https upstream.
• Adds a new configuration variable, proxy_pass_host, which determines whether nginx will forward the home assistant host or the frigate upstream host to the upstream in server headers and importantly, as the SSL SNI host.
• Removes the separate upstream.conf in nginx, because we weren't (and probably aren't going to) use the load balancing features, and providing the upstream URI directly in the proxy configuration makes switching between http and https easier.
• Updates version number and changelog.

This might require some testing to see how it behaves if someone already using an HTTP server upgrades. It likely requires a configuration update to add http:// to the beginning of the server option.

This PR addresses #112.

If there are other changes or code style things that need to happen, let me know, I'm happy to take a look.

[Quedale]

Thanks antonjs, I was just starting to look for exactly that!

I need to look at how to build the add-on first, but I will try to test your change when I get a chance.

[Quedale]

Well that went smoothly. I forgot how easy it was to add a custom add-on.

I managed to successfully test your changes and everything works as expected. That's a :thumbsup: from me!

That effectively closes the loop on completely securing my environment. Thanks again!

[OnFreund]

Is there an ETA for a release with this PR?