Close xapian database even if error occurs.
Close xapian database even if error occurs.

* wqflask/wqflask/database.py (xapian_database,
xapian_writable_database): Close xapian database even if error occurs.

genenetwork/genenetwork2,genenetwork/genenetwork2,genenetwork/genenetwork2,genenetwork/genenetwork2