ReplicateRefUpdate: remove unnecessary factory method

The only difference in the signature of the two create methods was in
one parameter type: Set vs ImmutableSet. Since ImmutableSet is a subtype
of Set we can remove the method with the ImmutableSet in the parameter
type.

Note that ImmutableSet.copyOf(Collection c) is smart enough to not
create a copy of the passed collection when it is an ImmutableSet.

Change-Id: Ifc689027d17ff7ebdcab36b3f70a0adaf7942f09
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 f603466..7149cce 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
@@ -95,12 +95,6 @@
           project, ImmutableSet.copyOf(refs), uri.toASCIIString(), remote);
     }
 
-    public static ReplicateRefUpdate create(
-        String project, ImmutableSet<String> refs, URIish uri, String remote) {
-      return new AutoValue_ReplicationTasksStorage_ReplicateRefUpdate(
-          project, refs, uri.toASCIIString(), remote);
-    }
-
     public abstract String project();
 
     public abstract ImmutableSet<String> refs();