Fix SelfEquals error reported by error-prone

Change-Id: I48de373a5b257c79481e1eadd1a814e8d7fcff50
diff --git a/src/test/java/com/ericsson/gerrit/plugins/syncindex/IndexEventHandlerTest.java b/src/test/java/com/ericsson/gerrit/plugins/syncindex/IndexEventHandlerTest.java
index 6489602..4bc0eec 100644
--- a/src/test/java/com/ericsson/gerrit/plugins/syncindex/IndexEventHandlerTest.java
+++ b/src/test/java/com/ericsson/gerrit/plugins/syncindex/IndexEventHandlerTest.java
@@ -116,8 +116,9 @@
   public void testSyncIndexTaskHashCodeAndEquals() {
     SyncIndexTask task = indexEventHandler.new SyncIndexTask(CHANGE_ID, false);
 
-    assertThat(task.equals(task)).isTrue();
-    assertThat(task.hashCode()).isEqualTo(task.hashCode());
+    SyncIndexTask sameTask = task;
+    assertThat(task.equals(sameTask)).isTrue();
+    assertThat(task.hashCode()).isEqualTo(sameTask.hashCode());
 
     SyncIndexTask identicalTask =
         indexEventHandler.new SyncIndexTask(CHANGE_ID, false);