Unable to delete field variables via push publish

[bryanboza]

We need implement the way to delete the field variables of any field when you try to update some content type via push publish

Expected Behavior

The system should be able to delete the field variable if in the sender this one does not exist anymore

Current Behavior

The system update the field variables if you modify some one, or add a new one in case that does not exist, but is unable to delete if you was removed

Steps to Reproduce (for bugs)

1. Configure your push environment
2. Login as admin
3. Create a new content type
4. Add some fields, and add some field variables to the field
5. Push it
6. Delete some of the field variables of the field
7. Push again

Your Environment

Tested on master-4.1 // Postgres