remove ensureindex api (use postInit instead)

hydro/entry/master.ts

@@ -24,7 +24,6 @@ export async function load(call: Entry) {
     await fs.writeFile(lockfile, JSON.stringify(context));
     global.onDestory.push(() => {
         fs.removeSync(lockfile);
-        fs.emptyDirSync(tmpdir);
     });
     require('../lib/i18n');
     require('../utils');