Bug 663752 - Cert renewal for attrcrypt and encchangelog
    
    https://bugzilla.redhat.com/show_bug.cgi?id=663752
    
    Description: When changelog is encrypted and the certificate
    used for the encryption has a problem (e.g., expired, renewed,
    etc.), running the CL2LDIF task could crash the server.  This
    patch is adding more error checks for the decrypted result.
    If a problem is found, it skips the change.