remote: Move the call to remoteClientFreePrivateCallbacks from FreeFunc to CloseFunc

remote: Move the call to remoteClientFreePrivateCallbacks from FreeFunc to CloseFunc

Still because of commit id 'fe8f1c8b' where we generate a REF for the
Register and that's transparent to the consumer (e.g. how would they
know they need to ensure that Deregister is called), thus the purpose of
this patch is to find a way to Deregister if it's determined that the
consumer hasn't by the time of the "last" REF we'd have.

This solution to this problem is to alter the processing to have the
remoteClientCloseFunc handle performing the Deregister calls instead of
the remoteClientFreeFunc because there's no way FreeFunc would be called
unless the Deregister was already called.