Upgrade: add PKI drop-in file if missing
    
    During the installation of IPA server, the installer adds a drop-in
    file in /etc/systemd/system/pki-tomcatd@pki-tomcat.service.d/ipa.conf
    that ensures the CA is reachable before the start command returns.
    If the file is missing (for instance because the server was installed
    with an old version before this drop-in was created), the upgrade
    should add the file.
    
    Fixes: https://pagure.io/freeipa/issue/9381
    
    Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>