fix: change when to clear a debugger

Signed-off-by: yukke42 <yusuke.muramatsu@tier4.jp>

Author: yukke42

perception/image_projection_based_fusion/src/fusion_node.cpp

@@ -153,10 +153,6 @@ void FusionNode<Msg>::fusionCallback(
     return;
   }
 
-  if (debugger_) {
-    debugger_->clear();
-  }
-
   Msg output_msg = *input_msg;
 
   preprocess(output_msg);
@@ -197,6 +193,9 @@ void FusionNode<Msg>::fusionCallback(
       RCLCPP_WARN(this->get_logger(), "no camera info. id is %zu", image_id);
       continue;
     }
+    if (debugger_) {
+      debugger_->clear();
+    }
 
     fuseOnSingleImage(
       *input_msg, image_id, *input_roi_msg, camera_info_map_.at(image_id), output_msg);