fix: allow logging in when using production mode locally

It hasn't been possible to log in when running production mode locally. I've just discovered that it's the use of NODE_ENV causing broken configuration when not running the site on a prereview.org domain. 66f2dfd had caused the NODE_ENV to be 'production' locally.

Using the NODE_ENV to change settings will always create problems; instead, we can calculate the setting based on the ORCID callback URL, which will work no matter where we run the site.

Refs #395

src/backend/server.js

@@ -253,7 +253,7 @@ export default async function configServer(config) {
   }
 
   // Manual override of domain to allow for outbreaksci.* subdomain
-  const sessionOpts = config.isProd ? { domain: 'prereview.org' } : {};
+  const sessionOpts = { domain: new URL(config.orcidCallbackUrl).hostname };
 
   server
     .use(compress())