Revert "add expanduser to db_filename". It's a no-op after b936454.
Revert "add expanduser to db_filename". It's a no-op after b936454.

This reverts commit 15b53ef2420e7192b63960cb8b48cbe8d45f8684.

psung/zeya,lifeeth/Zeya,lifeeth/Zeya,psung/zeya