ipa-backup: backup the PKCS module config files setup by IPA
    
    ipa installer creates /etc/pkcs11/modules/softhsm2.module in order
    to disable global p11-kit configuration for NSS.
    This file was not included in the backups, and not restored.
    
    The fix adds the file to the list of files to include in a backup.
    
    Fixes: https://pagure.io/freeipa/issue/8073
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>