message: core: the != nullptr test is not needed
diff: @@ -433,7 +433,7 @@ bool MavsdkImpl::does_system_exist(uint8_t system_id)
  void MavsdkImpl::notify_on_discover(const uint64_t uuid)
  {
  - if (_on_discover_callback != nullptr) {
  + if (_on_discover_callback) {
  _on_discover_callback(uuid);
  }
  }
  @@ -441,7 +441,7 @@ void MavsdkImpl::notify_on_discover(const uint64_t uuid)
  void MavsdkImpl::notify_on_timeout(const uint64_t uuid)
  {
  LogDebug() << "Lost " << uuid;
  - if (_on_timeout_callback != nullptr) {
  + if (_on_timeout_callback) {
  _on_timeout_callback(uuid);
  }
  }
  