message: camera: check that we have a camera before testing
diff: #include <atomic>
  #include <future>
  #include "dronecore.h"
  +#include "system.h"
  #include "integration_test_helper.h"
  #include "camera_test_helpers.h"
  @@ -20,6 +21,7 @@ TEST(CameraTest, ShowSettings)
  std::this_thread::sleep_for(std::chrono::seconds(2));
  System &system = dc.system();
  + ASSERT_TRUE(system.has_camera());
  auto camera = std::make_shared<Camera>(system);
  // Wait for download to happen.
  @@ -68,6 +70,7 @@ TEST(CameraTest, SettingsAnySetting)
  std::this_thread::sleep_for(std::chrono::seconds(2));
  System &system = dc.system();
  + ASSERT_TRUE(system.has_camera());
  auto camera = std::make_shared<Camera>(system);
  // FIXME: we need to wait for the camera definition to be ready
  