avoid adding render updates for deleted clients after animation completes
avoid adding render updates for deleted clients after animation completes

Summary:
in the case where deletion is deferred to preserve a window animation this
codepath may be triggered by a deleted client, at which point no render update
should occur in order to avoid compositor errors

ref f78eb3c108fbbb84edcb4c62fc499b4be558169a
fix T5203

Reviewers: ManMower, devilhorns

Reviewed By: devilhorns

Subscribers: netstar, cedric

Tags: #enlightenment-git

Maniphest Tasks: T5203

Differential Revision: https://phab.enlightenment.org/D6367

tasn/enlightenment,tasn/enlightenment,tasn/enlightenment