Fix documentation issue

Task sharding was removed in a revert previuosly but the
documentation was still pointing to it. Fixed it to reflect
the current logic.

Change-Id: If888518a2485a72c6a692aa377bdab1fb1b8cd75
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
index e1b1c0a5..35ecec6 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
@@ -50,14 +50,11 @@
  * <p><code>
  *   .../building/<tmp_name>                       new replication tasks under construction
  *   .../running/<sha1>                            running replication tasks
- *   .../waiting/<task_sha1_NN_shard>/<task_sha1>  outstanding replication tasks
+ *   .../waiting/<task_sha1>  outstanding replication tasks
  * </code>
  *
  * <p>Tasks are moved atomically via a rename between those directories to indicate the current
  * state of each task.
- *
- * <p>Note: The .../waiting/<task_sha1_NN_shard> directories are never removed. This helps prevent
- * failures when moving tasks to and from the shard directories from different hosts concurrently.
  */
 @Singleton
 public class ReplicationTasksStorage {