Bugfix for the postgres / timescaledb users who have experienced the rare bug of "26000: prepared statement "_p1" does not exist" during database operations. It is unknown whether this is a bug in the C# postgres driver or intended behavior. Regardless, OhmGraphite would enter an infinite loop trying to insert sensor data. The fix is to now on db failure, in addition to re-instantiating a connection, to purge all persisted prepared statements.