Rebase: Fix CurrentRevision in NoteDb

This caller was missed long ago when we refactored everything to use
PatchSetUtil to look up PatchSets. Probably not coincidentally because
it was never tested, nor indeed plumbed into ChangeApi.

Change-Id: Ib77304286df14f22370375911bb59bd8bd3e6356

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/changes/ChangeApi.java

@@ -114,6 +114,12 @@ public interface ChangeApi {
   /** Publishes a draft change. */
   void publish() throws RestApiException;
 
+  /** Rebase the current revision of a change using default options. */
+  void rebase() throws RestApiException;
+
+  /** Rebase the current revision of a change. */
+  void rebase(RebaseInput in) throws RestApiException;
+
   /** Deletes a change. */
   void delete() throws RestApiException;
 
@@ -315,6 +321,16 @@ public interface ChangeApi {
       throw new NotImplementedException();
     }
 
+    @Override
+    public void rebase() {
+      throw new NotImplementedException();
+    }
+
+    @Override
+    public void rebase(RebaseInput in) {
+      throw new NotImplementedException();
+    }
+
     @Override
     public void delete() {
       throw new NotImplementedException();