fix captcha

@@ -15,7 +15,7 @@ const isGeetest = (req) => {
 };
 
 function required(req, res, next) {
-    img.trySwitch(req).then(() => {
+    img.trySwitch(req, res).then(() => {
         if (req.session.captcha.type === CAPTCHA_TYPE.image && req.session.captcha.value === CAPTCHA_SWITCH.off) {
             const captcha = {
                 type: CAPTCHA_TYPE.geetest,
@@ -23,7 +23,7 @@ function required(req, res, next) {
             };
 
             req.session.captcha = captcha;
-            res.app.locals.captcha = captcha;
+            res.locals.captcha = captcha;
         }
         next();
     }).catch(next);
@@ -62,7 +62,7 @@ const geeOnly = function(req, res, next) {
     };
 
     req.session.captcha = captcha;
-    res.app.locals.captcha = captcha;
+    res.locals.captcha = captcha;
 
     next();
 };

@@ -56,7 +56,7 @@ const checkAPI = (req, res, next) => {
     }).catch(next);
 };
 
-const trySwitch = (req) => {
+const trySwitch = (req, res) => {
     return req.ctx(CaptchaServiceModel).try().then((result) => {
         const captcha = {
             type: CAPTCHA_TYPE.image,
@@ -64,7 +64,7 @@ const trySwitch = (req) => {
         };
 
         req.session.captcha = captcha;
-        req.app.locals.captcha = captcha;
+        res.locals.captcha = captcha;
     });
 };