Updated mailgun settings view mode in admin-x

refs https://github.com/TryGhost/Team/issues/3151

- updates view mode for when mailgun is setup in settings

ghost/admin-x-settings/src/components/settings/email/Mailgun.tsx

@@ -29,19 +29,9 @@ const MailGun: React.FC = () => {
 
     const data = isMailgunSetup ? [
         {
-            heading: 'Mailgun region',
-            key: 'mailgun-region',
-            value: mailgunRegion
-        },
-        {
-            heading: 'Mailgun domain',
-            key: 'mailgun-domain',
-            value: mailgunDomain
-        },
-        {
-            heading: 'Mailgun private API key',
-            key: 'commenting',
-            value: mailgunApiKey
+            heading: 'Status',
+            key: 'status',
+            value: 'Mailgun is set up ✅'
         }
     ] : [
         {