update mru_cache in replicated_dets before calling child callbacks
update mru_cache in replicated_dets before calling child callbacks

to eliminate race between cache update and version change.

now it is guaranteed that cache has update that corresponds to
the latest storage version

Change-Id: I9da54cfd8caaa8627766636243da8705106a3b3c
Reviewed-on: http://review.couchbase.org/78213
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>

membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server