Steps to reproduce.
Pre-conditions:
1. Trigger action configured to notify other users about problem updates.
2. Have second user (test-user), which is configured with Media type (for example email) and with permissions to tested hosts and problems.

The case:

1. Act with Admin user.
2. Have two ongoing problems: 1st is Cause and 2nd is Symptom:
   
3. Click update on Symptom problem.
4. Enter message and change severity, submit form.
5. Go to Reports-> Action log and observe that message for test-user about problem updating is sent - EXPECTED:
   
6. Go to Problems and again update Symptom problem, but this time enter the message, change severity AND tick the"Convert to Cause" checkbox. Submit update form.
   
7. Go to Reports-> Action log and observe that no any new notification is generated - NOT EXPECTED.

Expected:
Message should be sent to notify other users that problem was updated and ranking was changed among the other fields.