vitessdriver: fix json configuration test
vitessdriver: fix json configuration test

Signed-off-by: Derek Perkins <e1c79a582b6629e6b39e9679f4bb964d25db4aa8@nozzle.io>

mahak/vitess,mahak/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,mahak/vitess,mahak/vitess,mahak/vitess