refactor(frontend-integration): inline-import http-proxy-middleware

If no dev-dependencies are installed, the unconditional
import crashes the app.

Signed-off-by: David Mehren <git@herrmehren.de>

src/main.ts

@@ -52,7 +52,7 @@ async function bootstrap(): Promise<void> {
       `Serving OpenAPI docs for private api under '/private/apidoc'`,
       'AppBootstrap',
     );
-    setupFrontendProxy(app, logger);
+    await setupFrontendProxy(app, logger);
   }
 
   await setupSpecialGroups(app);