Fix compile error

Author: kderusso

x-pack/plugin/ent-search/src/main/java/org/elasticsearch/xpack/application/EnterpriseSearch.java

@@ -29,6 +29,7 @@
 import org.elasticsearch.plugins.SystemIndexPlugin;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestHandler;
+import org.elasticsearch.search.rank.RankDoc;
 import org.elasticsearch.xcontent.ParseField;
 import org.elasticsearch.xpack.application.analytics.AnalyticsTemplateRegistry;
 import org.elasticsearch.xpack.application.analytics.action.DeleteAnalyticsCollectionAction;