Description of problem:
When opening the edit vm dialog in the ui and closing it using the "ok" button an error appears that states that a locked field was edited. 
The bug was found on 3.6.6 snapshot. 
It does not reproduce on 3.6.5

Version-Release number of selected component (if applicable): 3.6.6


How reproducible: 3/3


Steps to Reproduce:
1. Have a hosted engine vm.
2. Open the edit vm dialog.
3. Don't change anything and click on "ok". 

Actual results:
An error appears stating a locked field is being edited. 

Expected results:
The dialog should close. The vm shouldn't change in the db. 

Additional info:
The bug can also be reproduced via api (update vm).
After some research it appears that the parameters that are passed to the backend contain some fields that are changed even though nothing was changed.
Those parameters are: dbGeneration, interfaces, quotaEnforcmentType and vmInit. The error is caused due to a change in vmInit. The expected value is null and the received is an empty object.