Revert "/admin/users: Limit data sent"

Due to a limitation in DBIx::Class, the only way to prefetch data for a
has_many relationship is to prefetch all of the columns. Until/unless
that's fixed, we'll just use the full prefetch here.

This reverts commit b9ca5b78010f86aae06d882405e0ab30868ce6cd.

Signed-off-by: Shea Levy <shea@shealevy.com>