Action buttons "Add" and "Remove" are not clickable in Tags tab of host configuration form, if this form was opened after "Inherited and item tags" option was selected in Tags tab of Item configuration form (see attached gif).

Steps to reproduce:

1. Open configuration of any host
2. Open the list of items
3. Click on Create item button
4. In the opened configuration form select "Tags" tab
5. Select the "Inherited and item tags" option
6. Click on the Host name in breadcrumbs
7. In the opened Host configuration dialog select the "Tags" tab and attempt to press "Add" or "Remove" buttons.

Result: nothing happens when clicking the "Add" or "Remove" buttons
Expected: the corresponding action should take place after one of the above mentioned buttons is clicked on

Example: