CRM-18482 import - don't fill acl_contact_cache immediately before em…

[eileenmcnaughton]

…ptying it

[eileenmcnaughton]

@seamuslee001 do you want to do QA on this? I have put it on your ubox.

The point of this is to remove a case where acl caches are rebuilt, this reducing a potential cause of deadlocks. It seems to me that CRM_Contact_BAO_Contact_Utils::clearContactCaches() removes the entries created a few lines earlier by the call to CRM_ACL_BAO_Cache::updateEntry($userID);

I guess one question that is open in my mind is how this would be affected by moving to scheduled rebuilds of caches rather than opportunistic. I'm not sure that changes this PR, just keeps it on our radar for inclusion in that one.

[seamuslee001]

@andrew-cormick-dockery just FYI

[litespeedmarc]

@colemanw, this seems pretty simple fix from a pretty reliable contributor. Review looks simple enough. Can we move it along for merge please?