DOCSP-29587 Typo correction, mongos -> mongod (#3165)

Author: ianf-mongodb

source/core/sharded-cluster-components.txt

@@ -71,7 +71,7 @@ application and the ``mongos`` routers, you must configure it for
 :term:`client affinity`. Client affinity allows every connection from a 
 single client to reach the same ``mongos``. For shard-level high 
 availability, a common pattern is to place ``mongos`` instances on the 
-same hardware that ``mongos`` instances are already running on.
+same hardware that ``mongod`` instances are already running on.
 Another option is to embed ``mongos`` routers with
 application tier infrastructure.