fixed ValueError when processing bbox in XML annotation file
fixed ValueError when processing bbox in XML annotation file

jch1/models,derekjchow/models,xcyan/models,r888888888/models,wangyang59/tf_models,jazcollins/models,alexgorban/models,r888888888/models,jch1/models,alexgorban/models,jiaphuan/models,bousmalis/models,jazcollins/models,bousmalis/models,alexgorban/models,derekjchow/models,wangyang59/tf_models,r888888888/models,sshleifer/object_detection_kitti,wangyang59/tf_models,wangyang59/tf_models,jch1/models,alexgorban/models,hang-qi/models,xcyan/models,tombstone/models,tombstone/models,derekjchow/models,hang-qi/models,jiaphuan/models,jiaphuan/models,cshallue/models,hang-qi/models,cshallue/models,derekjchow/models,bousmalis/models,tombstone/models,bousmalis/models,jiaphuan/models,xcyan/models,derekjchow/models,sshleifer/object_detection_kitti,tombstone/models,jazcollins/models,xcyan/models,cshallue/models,cshallue/models,r888888888/models,wangyang59/tf_models,hang-qi/models,xcyan/models,jazcollins/models,hang-qi/models,sshleifer/object_detection_kitti,hang-qi/models,tombstone/models,tombstone/models,bousmalis/models,wangyang59/tf_models,jiaphuan/models,jch1/models,r888888888/models,bousmalis/models,jiaphuan/models,alexgorban/models,sshleifer/object_detection_kitti,jazcollins/models,sshleifer/object_detection_kitti,sshleifer/object_detection_kitti,jazcollins/models,cshallue/models,jch1/models,zbigniewwojna/text-rcnn,xcyan/models,r888888888/models,jch1/models