packaging: remove largefile-fileserver option from spec file

Remove the obsolete --enable-largefile-fileservers option from
the RedHat spec file.

Change-Id: I8334c0bfc53125243f78c04a064e23c987a2a4fc
Reviewed-on: http://gerrit.openafs.org/9144
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>