Allow aprilrobotics to start without camera extrinsics

This makes it so that it doesn't crash-loop prior to having extrinsics.

Change-Id: Ib7f494d5b2ab1504a6bffa0ed7606097707dc47c
Signed-off-by: James Kuszmaul <jabukuszmaul@gmail.com>
diff --git a/y2023/vision/target_mapping.cc b/y2023/vision/target_mapping.cc
index 921c172..419bd38 100644
--- a/y2023/vision/target_mapping.cc
+++ b/y2023/vision/target_mapping.cc
@@ -86,7 +86,7 @@
   auto detector_ptr = std::make_unique<AprilRoboticsDetector>(
       detection_event_loop, kImageChannel);
   // Get the camera extrinsics
-  cv::Mat extrinsics_cv = detector_ptr->extrinsics();
+  cv::Mat extrinsics_cv = detector_ptr->extrinsics().value();
   Eigen::Matrix4d extrinsics_matrix;
   cv::cv2eigen(extrinsics_cv, extrinsics_matrix);
   const auto extrinsics = Eigen::Affine3d(extrinsics_matrix);