Windows: HaveCallback vs OfflineRO Is Valid

Windows: HaveCallback vs OfflineRO Is Valid

commit f716962ab41847af4450d0a361f5de9195b32ed0
inadvertently broke the offline .readonly is valid functionality
when readonly volume versioning is disabled.  Restore it.

Reviewed-on: http://gerrit.openafs.org/7679
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit c3485a35b7a548d850d55dde4634ba78e5330aa9)

Change-Id: Ie7b4758fe14a0a695d7db1b04fc5039050891908
Reviewed-on: http://gerrit.openafs.org/8637
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>