Create type definition for 'recaptcha-promise' (#4068)

src/server/api/private/signup.ts

@@ -8,14 +8,13 @@ import Meta from '../../../models/meta';
 import RegistrationTicket from '../../../models/registration-tickets';
 import usersChart from '../../../chart/users';
 import fetchMeta from '../../../misc/fetch-meta';
+import * as recaptcha from 'recaptcha-promise';
 
 export default async (ctx: Koa.BaseContext) => {
 	const body = ctx.request.body as any;
 
 	const instance = await fetchMeta();
 
-	const recaptcha = require('recaptcha-promise');
-
 	// Verify recaptcha
 	// ただしテスト時はこの機構は障害となるため無効にする
 	if (process.env.NODE_ENV !== 'test' && instance.enableRecaptcha) {