judge: 错误详情上报

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.13.29",
+    "version": "2.13.30",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",

packages/hydrooj/src/handler/judge.ts

@@ -42,7 +42,7 @@ export async function next(body: JudgeResultBody) {
         const c: TestCase = {
             memory: body.case.memory,
             time: body.case.time,
-            message: body.case.message,
+            message: body.case.message || '',
             status: body.case.status,
         };
         rdoc.testCases.push(c);