minor: DOCS-309 link form change

Author: Sam Kleinman

source/administration/sharding-architectures.txt

@@ -131,7 +131,7 @@ potential failure scenarios and available resolutions:
   starts, it retrieves a copy of the :term:`config database` and can
   begin routing queries.
 
-- A single :term:`mongod` becomes unavailable in a shard.
+- A single :program:`mongod` becomes unavailable in a shard.
 
   :doc:`Replica sets </replication>` provide high availability for
   shards. If the unavailable :program:`mongod` is a :term:`primary`,