polybase-troubleshooting: fix typo

Author: Schneider

docs/relational-databases/polybase/polybase-troubleshooting.md

@@ -212,7 +212,7 @@ After configuring a set of machines as part of a PolyBase scale out group, you c
 PolyBase does not interface with Name Node HA services like Zookeeper or Knox today. However, there is a proven workaround that can be used to provide the functionality.
 
 Work Around:
-Use DNS name to reroute connections to the active Name Node. In order to do this, you will need to ensure that the External Data Source is using a DNS name to communicate with the Name Node. When Name Node Failover occurs, you will need to change the IP address associated with the DNS name used in the External Data Source definition. This will reroute all new connections to the correct Name Node. Existing connections will fail when failover occurs. To automate this process, a "heartbeat" can ping the active Name Node. If the heart beat fails, one can assume a failover has occured and automatically switch to the secondaries IP address.
+Use DNS name to reroute connections to the active Name Node. In order to do this, you will need to ensure that the External Data Source is using a DNS name to communicate with the Name Node. When Name Node Failover occurs, you will need to change the IP address associated with the DNS name used in the External Data Source definition. This will reroute all new connections to the correct Name Node. Existing connections will fail when failover occurs. To automate this process, a "heartbeat" can ping the active Name Node. If the heart beat fails, one can assume a failover has occurred and automatically switch to the secondaries IP address.
 
 ## Error messages and possible solutions