Fix internal_replication value

The `internal_replication` value is left `false` by default since only one replica per shard in this configuration.

Author: kdorichev

docs/deployment-guides/replication-sharding-examples/02_2_shards_1_replica.md

@@ -274,7 +274,7 @@ template for distributed DDL queries, which are queries that execute across the
 cluster using the `ON CLUSTER` clause. By default, distributed DDL queries
 are allowed, but can also be turned off with setting `allow_distributed_ddl_queries`.
 
-`internal_replication` is set to true so that data is written to just one of the replicas.
+`internal_replication` is left set to false by default since only one replica per shard.
 
 ```xml
 <remote_servers>