remove default expiry in jwt token

lib/units/auth/oauth2/index.js

@@ -39,6 +39,9 @@ module.exports = function(options) {
             , name: req.user.email.split('@', 1).join('')
             }
           , secret: options.secret
+          , header: {
+              exp: Date.now() + 24 * 3600
+            }
           })
         }))
       }