Fixed issue with group_serializer current_user exists

• Fixed:
- issue with group_serializer current_user exists

app/serializers/rest/group_serializer.rb

@@ -16,7 +16,11 @@ class REST::GroupSerializer < ActiveModel::Serializer
   end
 
   def password
-    if defined?(current_user) && object.group_accounts.where(account_id: current_user.account.id, role: :admin).exists?
+    if !defined?(current_user) || current_user.nil?
+      return nil
+    end
+
+    if object.group_accounts.where(account_id: current_user.account.id, role: :admin).exists?
       object.password
     else
       nil