Follow upstream's dropping of the PatchSetAncestors table

Gerrit core dropped the PatchSetAncestors table in
4ebea5bd673fcfac8ccecb1fa30098a1ad71466f, which made compiling against
current master fail.

Error message is (re-formatted to fit the commit message):

[...]/ReplayRevisionsStep.java:133: error: cannot find symbol
        ChangeUtil.insertAncestors(db, ps.getId(), commit);
                  ^
  symbol:   method insertAncestors([...].ReviewDb,[...].PatchSet.Id,[...].RevCommit)
  location: class com.google.gerrit.server.ChangeUtil

So we stop filling the table when importing.

Bug: Issue 3637
Change-Id: Ic7546b31b87a8bd25094ec3ffb582259f043b0dd
diff --git a/src/main/java/com/googlesource/gerrit/plugins/importer/ReplayRevisionsStep.java b/src/main/java/com/googlesource/gerrit/plugins/importer/ReplayRevisionsStep.java
index b4184b1..5adf74f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/importer/ReplayRevisionsStep.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/importer/ReplayRevisionsStep.java
@@ -130,8 +130,6 @@
           change.setCurrentPatchSet(info);
         }
 
-        ChangeUtil.insertAncestors(db, ps.getId(), commit);
-
         updateRef(repo, ps);
       }