Event Rule breaks if I delete a Contact used in an escalation

[martialblog]

Hoi,

while testing some stuff I noticed that, when I create an Event Rule with two escalations, first a Contact, then a Schedule - save it - and afterwards delete the Contact in the Contacts overview, the Event Rule cant be edited anymore cause of: Undefined array key 1

Regards,
Markus

[nilmerg]

Needs to be re-visited once #171 is done.