handle error on schemamanager.Run in grpc API
handle error on schemamanager.Run in grpc API

Signed-off-by: Phani Raj <e32426b86e9fbdda17f4aa1aca45727ffe36415d@planetscale.com>

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