Fix services' URL
    
    Seems that at some point in the history of this package, we've had
    %{import_path} defined. However, that's not the case anymore and it
    causes the following issue in the Documentation field of the services:
    
    ```
    fidencio@dahmer ~/src/fedora/kata-ksm-throttler $ systemctl cat kata-ksm-throttler.service
    ...
    Documentation=https://%{import_path}
    ...
    ```
    
    Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>