Remove unused import

Author: jasontedor

server/src/main/java/org/elasticsearch/transport/RemoteClusterAware.java

@@ -31,7 +31,6 @@
 import org.elasticsearch.common.settings.SettingUpgrader;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.transport.TransportAddress;
-import org.elasticsearch.common.util.set.Sets;
 
 import java.net.InetAddress;
 import java.net.InetSocketAddress;