Fix CA CRL migration crash in ipa-upgradeconfig
    
    CRL migrate procedure did not check if a CA was actually configured
    on an updated master/replica. This caused ipa-upgradeconfig to
    crash on replicas without a CA.
    
    Make sure that CRL migrate procedure is not run when CA is not
    configured on given master. Also add few try..except clauses to
    make the procedure more robust. There is also a small refactoring of
    "<service> is not configured" log messages, so that they have matching
    log level and message.
    
    dogtag.py constants were updated to have a correct path to new CRL
    directory on Fedora 18 (dogtag 10).
    
    https://fedorahosted.org/freeipa/ticket/3159