Fixed error message

backend-services/friend-service/src/Routes/FriendsRouter.ts

@@ -33,6 +33,6 @@ FriendsRouter.get('/', async (req:CustomJWTRequest, res:Response): Promise<void>
   return friendManager.RemoveFriend(user_id, friend_id).then(result => {
     return res.sendStatus(200);
   }).catch((error: Error) => {
-    return res.status(400).json({error: error})
+    return res.status(400).json({error: error.message})
   });
 });
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