Fix incorrect detect structure test

Change-Id: I7062f3639147c40b57947790d3b18331a39a366b

internal/ceres/detect_structure_test.cc

diff --git a/internal/ceres/detect_structure_test.cc b/internal/ceres/detect_structure_test.cc
index 533f49f..a701a19 100644
--- a/internal/ceres/detect_structure_test.cc
+++ b/internal/ceres/detect_structure_test.cc
@@ -271,8 +271,8 @@
     row.block.size = 2;
     row.block.position = 0;
     row.cells.push_back(Cell(0, 0));
+    row.cells.push_back(Cell(1, 0));
     row.cells.push_back(Cell(2, 0));
-    row.cells.push_back(Cell(3, 0));
   }
 
   int row_block_size = 0;