message: protocol.Serializer: Don't emit pings below version 0.3.
diff: @@ -206,7 +206,7 @@ namespace elle
  {
  if (bool(this->_ping_period) != bool(this->_ping_delay))
  elle::err("specify either both ping period and timeout or neither");
  - if (this->_ping_period)
  + if (this->_ping_period && this->version() >= elle::Version(0, 3, 0))
  this->_pinger_handler({});
  }
  