By design Gitlab currently symlinks *.git/hooks to hooks in gitlab-shell
working tree. As when restoring backup on different machine gitlab-shell
worktree can be located in another place, all hooks needs to be adjusted
upon restoration.

Btw, Gitlab itself does the same:

    https://gitlab.com/gitlab-org/gitlab-ce/blob/7383453b/lib/backup/repository.rb#L103
    https://gitlab.com/gitlab-org/gitlab-ce/commit/1d03fa2e

/cc @kazuhiko