configure: use "--disable-uuid" instead of "--without-uuid"

Reported by Kevin Coffman and Jonathan Andrews.  Apparently --without-uuid
doesn't work with some older versions of autoconf, so correct the help text
to document the option that actually does the trick.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>