Make the vision solver use a less strict problem.

Solve a 4 point with distance to lines and use if the 8 point problem
isn't solvable.

Change-Id: Ie0e4f5983b35cbe2fc64af8230c7e1e1cbd53aaa
diff --git a/y2019/vision/debug_viewer.cc b/y2019/vision/debug_viewer.cc
index 14063c2..8ef67fa 100644
--- a/y2019/vision/debug_viewer.cc
+++ b/y2019/vision/debug_viewer.cc
@@ -166,7 +166,7 @@
     }
 
     // Check that our current results match possible solutions.
-    results = target_finder_.FilterResults(results, 0);
+    results = target_finder_.FilterResults(results, 0, draw_results_);
     if (draw_results_) {
       for (const IntermediateResult &res : results) {
         DrawTarget(res, {0, 255, 0});