Comment 4 for bug 1847453

Reviewed: https://review.opendev.org/687872
Committed: https://git.openstack.org/cgit/openstack/kuryr-kubernetes/commit/?id=7444eab6494af92dc75ecb5c47e8f1f0299fbf61
Submitter: Zuul
Branch: stable/train

commit 7444eab6494af92dc75ecb5c47e8f1f0299fbf61
Author: Luis Tomas Bolivar <email address hidden>
Date: Wed Oct 9 11:41:37 2019 +0200

    Avoid namespace deletion error if processing a duplicated event

    In case of a kuryr-controller restart, if the namespace deletion
    event was already executed and it is retriggered, it can make the
    kuryr-controller fail as the kuryrnet CRD would have been already
    deleted and we cannot obtain the subnet id from it. In that case
    the event just need to be skip.

    Change-Id: I14fcf820d94319541dd7bf13893e82cf0373969c
    Closes-Bug: 1847453
    (cherry picked from commit efae1f5211e3907ff58853155b785f0e8fb34e9b)