LU-9776 lustre-client cannot be installed if both client and server repos are configured

LU-9776 lustre-client cannot be installed if both client and server repos are configured

Due to current Obsoletes: tags on lustre-client, the client cannot be
installed on nodes where the client and server repos are configured.

Update the Obsoletes: to only obsolete previous lustre-client versions,
not the current one.

Signed-off-by: Brian J. Murrell <brian.murrell@intel.com>
Change-Id: Ie2f022967fd6f65030feeb23ea9637dce505054a
Reviewed-on: https://review.whamcloud.com/28065
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Minh Diep <minh.diep@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>