Revert "pjsip_location: Delete contact_status object when contact is deleted"

This reverts commit 0a9941de.

Matt,

This patch causes another problem and should not have been needed.
Before this patch, persistent_endpoint_contact_deleted_observer WAS
deleting the contact_status when ast_sip_location_delete_contact was
called.  By deleting it yourself in ast_sip_location_delete_contact
it was gone before the observer could run and the observer therefore
was throwing an error and not sending stasis/AMI/statsd messages.

So, I don't think this was the cause of your original issue.  I also
had verified the contact AMI and statsd lifecycle and it was working.
I'll double check now though.

ASTERISK-25675
Reported-by: Daniel Journo

Change-Id: Ib586a6b7f90acb641b0c410f659743ab90e84f1a