LU-3012 ubuntu: fix client module build

Add --disable-servers to confgiure command when
building the client modules.

Signed-off-by: Robert Read <robert.read@intel.com>
Change-Id: Ie29bf9336c476dd0b8b04b4601d409c4bc7f90f1
Reviewed-on: http://review.whamcloud.com/5804
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Brian J. Murrell <brian.murrell@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>