Enable psearch on upgrades
    
    From IPA 3.0, persistent search is a preferred mechanism for new DNS
    zone detection and is also needed for other features (DNSSEC, SOA
    serial updates).
    
    Enable psearch and make sure connections attribute is right. This
    step is done just once for a case when user switched the persistent
    search back to disabled on purpose.
    
    ipa-upgradeconfig was updated to accept --debug option in case
    somebody would want to see debug messages.