fix

@@ -63,7 +63,7 @@ const trySwitch = (req) => {
             value: result ? CAPTCHA_SWITCH.on : CAPTCHA_SWITCH.off
         };
 
-        req.session.capthca = captcha;
+        req.session.captcha = captcha;
         req.app.locals.captcha = captcha;
     });
 };