core: add fallback domain info

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "3.3.0",
+    "version": "3.3.1",
     "bin": "bin/hydrooj.js",
     "main": "src/loader",
     "module": "src/loader",

packages/hydrooj/src/service/server.ts

@@ -521,6 +521,7 @@ export class Handler extends HandlerCommon {
             this.args.domainId = 'system';
             this.user = await user.getById('system', this.session.uid);
             if (!this.user) this.user = await user.getById('system', 0);
+            this.domain = inferDomain || await domain.get('system');
             throw new NotFoundError(domainId);
         }
         this.UiContext.domainId = this.domainId;