Description of problem:
When I tried to create report using 5 fields from Virtual Machines, I had to wait for 10-20 seconds after each click. 
Furthermore, there was no any notification from UI that it performs some action. So, I thought that nothing happened and kept on clicking add button.

The same happenes when I remove already added field.

Version-Release number of selected component (if applicable):
5.8.0.12

How reproducible:
100%

Steps to Reproduce:
1. Open Cloud Intel->Reports
2. Click Reports accordion->All Reports
3. Then click Configuration->Add a new Report
4. Choose Virtual Machines from "Base the report on" dropdown
5. Try to add one/several fields several times

Actual results:
Fields are added very slowly. There is no any notification in UI that field is being added

Expected results:
Adding/Removing fields shouldn't be so slow.