python2-ipalib: add missing python dependency
    
    Commit dfd560a190cb2ab13f34ed9e21c5fb5c6e793f18 started to use
    ssl symbols like ssl.OP_NO_SSLv2 that were introduced in Python 2.7.9.
    
    Related https://pagure.io/freeipa/issue/6920
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>