Remove SERVER_NAME usage because could be localhost with reverse proxies

[yoyos]

I had problem with localhost values for a long time now because I always used reverse proxies like nginx or today traefik

Check my tickets:
1 year, 6 months: https://wordpress.org/support/topic/ogurl-is-always-localhost/
A few days: https://wordpress.org/support/topic/ogurl-localhost-continuing/

I tested those changes and if home_url is correctly set in general settings, I had no problem displaying og:url on frontpage or everywhere else

[yoyos]

I saw that I had multiple og:image with same image url that was causing errors with facebook debugger, changed that too.

[chuckreynolds]

Hey @yoyos I like the array unique; quick fix.
As for the local host values I'd have to test it and i don't have the time for local env setup and all the test scenarios.
I don't have an ETA on when I'd get to that but... this plugin is old... still functional but it needs a refactor pretty bad. I've had plans for that for a while but client work and life are priority.

That said with the image array I was going to have much different logic for that moving forward as FB linter has changed how they handle images drastically from how they used to when this version was released.