Add sortkey to FakeIndex to fix tests

Change-Id: I2083bcafd401b4037c85e12225b1a280eb2e1e51
diff --git a/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeIndex.java b/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeIndex.java
index 88d6b85..dd1a69e 100644
--- a/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeIndex.java
+++ b/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeIndex.java
@@ -31,7 +31,8 @@
   static Schema<ChangeData> V2 = new Schema<ChangeData>(2, false,
     ImmutableList.of(
       ChangeField.STATUS,
-      ChangeField.FILE));
+      ChangeField.FILE,
+      ChangeField.SORTKEY));
 
   private static class Source implements ChangeDataSource {
     private final Predicate<ChangeData> p;