ubik: disambiguate "Synchonize database with server" msgs

ubik: disambiguate "Synchonize database with server" msgs

Ubik issues the same message in two very different cases:
- sync server issues DISK_GetFile to obtain the latest version
- non-sync server receives DISK_SendFile from the sync server

Modify the messages so they provide more information and are
distinguishable from each other.

Change-Id: I99e8adc7229260f478a0df15791216e090d2e113
Reviewed-on: https://gerrit.openafs.org/12615
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>