feat(ui): Move PROXY setting to UI (#782)

Users who have set PROXY=yes in their Docker containers will need to configure this setting in the UI and restart the container.

server/index.ts

@@ -61,7 +61,7 @@ app
     startJobs();
 
     const server = express();
-    if (process.env.PROXY === 'yes') {
+    if (settings.main.trustProxy) {
       server.enable('trust proxy');
     }
     server.use(cookieParser());