Preconditions:

Availability of a trigger action in active state with one or more conditions.

Availability of a template with a trigger inside.

Availability of a host with above mentioned template.

Steps to reproduce:

1. Go to Alerts - Actions
2. Select an active trigger action, 
3. Add a new condition to the action, like "Trigger is equal to..." (choose the trigger)
4. Refresh (save) the action.
5. Go to Data collection - Hosts
6. Click on the required host and find the Templates field.
7. Click on Unlink or Unlink and clear next to the template to unlink the template.
8. Click on Update in the host attributes form.
9. Check the state of an action in action list

Result:
The action is automatically disabled
Expected:
The action is not disabled when there is more than one condition inside.