Added missing validator to updateSetup method

- This is the code corresponding to processArgs function in v1 authentication.updateSetup method

core/server/api/v2/utils/validators/input/index.js

@@ -3,6 +3,10 @@ module.exports = {
         return require('./passwordreset');
     },
 
+    get setup() {
+        return require('./setup');
+    },
+
     get posts() {
         return require('./posts');
     },

core/server/api/v2/utils/validators/input/setup.js

@@ -0,0 +1,12 @@
+const debug = require('ghost-ignition').debug('api:v2:utils:validators:input:updateSetup');
+const common = require('../../../../../lib/common');
+
+module.exports = {
+    updateSetup(apiConfig, frame) {
+        debug('resetPassword');
+
+        if (!frame.options.context || !frame.options.context.user) {
+            throw new common.errors.NoPermissionError({message: common.i18n.t('errors.api.authentication.notTheBlogOwner')});
+        }
+    }
+};