core: 修复ProblemDetail.title被翻译的问题

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.20.30",
+    "version": "2.20.31",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",

packages/hydrooj/src/handler/problem.ts

@@ -164,7 +164,7 @@ export class ProblemDetailHandler extends ProblemHandler {
             path: [
                 ['Hydro', 'homepage'],
                 ['problem_main', 'problem_main'],
-                [this.pdoc.title, null, true],
+                [this.pdoc.title, null, null, true],
             ],
         };
         this.extraTitleContent = this.pdoc.title;