judge: 修复java编译异常的问题

packages/hydrojudge/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@hydrooj/hydrojudge",
-    "version": "2.0.14",
+    "version": "2.0.15",
     "main": "package.json",
     "author": "masnn",
     "dependencies": {

packages/hydrojudge/src/compile.ts

@@ -10,6 +10,7 @@ export = async function compile(
     const LANGS = yaml.safeLoad(await global.Hydro.model.system.get('hydrojudge.langs'));
     if (!LANGS[lang]) throw new SystemError(`不支持的语言：${lang}`);
     const info = LANGS[lang];
+    target = info.target || target;
     const f = {};
     if (info.type === 'compiler') {
         copyIn[info.code_file] = { content: code };