message: core: fix unnecessary casts
diff: @@ -704,7 +704,7 @@ std::pair<MAVLinkParameters::Result, int> SystemImpl::get_param_ext_int(const st
  auto res = prom->get_future();
  MAVLinkParameters::ParamValue value_type;
  - value_type.set_int32(0.0f);
  + value_type.set_int32(0);
  _params.get_param_async(
  name,
  @@ -733,7 +733,7 @@ void SystemImpl::get_param_float_async(const std::string &name, get_param_float_
  void SystemImpl::get_param_int_async(const std::string &name, get_param_int_callback_t callback)
  {
  MAVLinkParameters::ParamValue value_type;
  - value_type.set_int32(0.0f);
  + value_type.set_int32(0);
  _params.get_param_async(
  name, value_type, std::bind(&SystemImpl::receive_int_param, _1, _2, callback));
  @@ -752,7 +752,7 @@ void SystemImpl::get_param_ext_float_async(const std::string &name,
  void SystemImpl::get_param_ext_int_async(const std::string &name, get_param_int_callback_t callback)
  {
  MAVLinkParameters::ParamValue value_type;
  - value_type.set_int32(0.0f);
  + value_type.set_int32(0);
  _params.get_param_async(
  name, value_type, std::bind(&SystemImpl::receive_int_param, _1, _2, callback), true);
  