Fix generation of owner group in GroupDetail.

Set the GroupDetail.ownerGroup to the AccountGroup.ownerGroupUUID
instead of the groupUUID.

Change-Id: I2d9b3fe19d5fd495956bdc690e462445fe87c652
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/account/GroupDetailFactory.java b/gerrit-server/src/main/java/com/google/gerrit/server/account/GroupDetailFactory.java
index 6bb31b3..2d455e9 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/account/GroupDetailFactory.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/account/GroupDetailFactory.java
@@ -67,7 +67,7 @@
     final AccountGroup group = control.getAccountGroup();
     final GroupDetail detail = new GroupDetail();
     detail.setGroup(group);
-    AccountGroup ownerGroup = groupCache.get(group.getGroupUUID());
+    AccountGroup ownerGroup = groupCache.get(group.getOwnerGroupUUID());
     if (ownerGroup != null) {
       detail.setOwnerGroup(GroupReference.forGroup(ownerGroup));
     }