Fix issue with M2M tokens on getChallenge

Author: ThomasKranitsas

src/services/ChallengeService.js

@@ -500,9 +500,10 @@ async function getChallenge (currentUser, id) {
   // delete challenge.typeId
 
   // Remove privateDescription for unregistered users
-  if (currentUser) {
+  if (currentUser && !currentUser.isMachine) {
     const ids = await helper.listChallengesByMember(currentUser.userId)
     if (!_.includes(ids, challenge.id)) {
+      _.unset(challenge, 'privateDescription')
     }
   } else {
     _.unset(challenge, 'privateDescription')