Fix recursion error events models

Ghost User
2020-03-04T21:54:10+01:00

Closes #1015 #1018

#### Previous behaviour
Steps to reproduce:

1. Save a published event after changing it to unpublished
2. Remove a published event

#### New behaviour
Steps to validate that it works:

1. Save a published event after changing it to unpublished
2. Remove a published event