Adapt checks plugin after change I22e4a571f

I22e4a571f moved the Sequences class to the server package. Adapting the
checks plugin.

Release-Notes: skip
Change-Id: I67594d37eb92874fe9f0969590c72861eee4514e

javatests/com/google/gerrit/plugins/checks/acceptance/CheckerRefsIT.java

diff --git a/javatests/com/google/gerrit/plugins/checks/acceptance/CheckerRefsIT.java b/javatests/com/google/gerrit/plugins/checks/acceptance/CheckerRefsIT.java
index dfeeb11..b0defa4 100644
--- a/javatests/com/google/gerrit/plugins/checks/acceptance/CheckerRefsIT.java
+++ b/javatests/com/google/gerrit/plugins/checks/acceptance/CheckerRefsIT.java
@@ -34,8 +34,8 @@
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.plugins.checks.CheckerRef;
 import com.google.gerrit.plugins.checks.CheckerUuid;
+import com.google.gerrit.server.Sequences;
 import com.google.gerrit.server.change.ChangeInserter;
-import com.google.gerrit.server.notedb.Sequences;
 import com.google.gerrit.server.update.BatchUpdate;
 import com.google.gerrit.server.util.time.TimeUtil;
 import com.google.inject.Inject;