Update to upstream openvpn-2.4.2
    
    Also:
      - Switching back to OpenSSL 1.0, via compat-openssl10 and
        compat-openssl10-pkcs11-helper (rhbz#1443749, rhbz#1432125, rhbz#1440468)
      - Re-enable --enable-x509-alt-username which got removed during the clean-up
        patches (rhbz#1443942)
      - Build with lz4 library from Fedora