Rewrite/set order issue

[jprelph]

Due to the use of set in regards to 'set $upstream_backend' there's an issue adding rewrite rules in using the ADD_NGINX_LOCATION_CFG as this breaks, for instance adding rewrite ^/path(.*) $1 break to remove the location will cause proxy_pass to break.

Changing the order of the rewrite module directives works, so an ADD_NGINX_LOCATION_CFG set to set $backend_upstream 'https://example.com'; rewrite ^/path(.*) $1 break does work.

While this is a valid workaround I think it's hard to discover - there's a few ways I can see to fix this - either moving set $backend_upstream "$proxy_address"; out of the template and inserting that before ${ADD_NGINX_LOCATION_CFG} in enable_location.sh (ie. so it appears before any added config) or creating a new ADD_REWRITE variable that could be added after the set $backend_upstream directive.

Happy to do a PR for either but I wasn't sure which was preferable.