improve aiopg connection cleanup
/usr/local/lib/python3.9/dist-packages/aiopg/pool.py:308: ResourceWarning: Unclosed 1 connections in <aiopg.pool.Pool object at 0xffff82f5cb80>
/usr/local/lib/python3.9/dist-packages/aiopg/pool.py:308: ResourceWarning: Unclosed 1 connections in <aiopg.pool.Pool object at 0xffff82f5cb80>