Fix collections import

app.py

@@ -2,7 +2,7 @@ import os
 os.system('git clone https://github.com/facebookresearch/detectron2.git')
 os.system('pip install -e detectron2')
 os.system("git clone https://github.com/microsoft/unilm.git")
-os.system("sed -i '/from collections import Iterable/c\from collections.abc import Iterable' unilm/dit/object_detection/ditod/table_evaluation/data_structure.py")
+os.system("sed -i 's/from collections import Iterable/from collections.abc import Iterable/' unilm/dit/object_detection/ditod/table_evaluation/data_structure.py")
 
 import sys
 sys.path.append("unilm")