Operating of synchronous master when no standby is available

I use Postgresql+Pacemaker+Corosync cluster with 2 Postgresql instances in synchronous replication mode. When one of the nodes is down, clients hang on INSERT operations because the primary server waits until standby confirms that it got the data, but the standby node is down.

I need clients to feel no difference when they operate with a fully operational cluster or with a degraded cluster containing primary node alone.

Is it possible to configure synchronous replication to operate normally when primary and replica are online, but primary no waits confirmation from replica if replica is not connected?

Best regards,
Sergey Cherukhin