This was causing crashing and corruption issues. This should have been
handled by the garbage collector, but for some reason old references
still hang around.
Add a "close" method to DamusState which disconnects from relays and
closes nostrdb.
Changelog-Fixed: Fix crash when logging out and switching accounts
Changelog-Fixed: Fix persistent local notifications even after logout
Signed-off-by: William Casarin <jb55@jb55.com>
4cf92756f1