pairPatchAgglomeration: Added call to compactLevels at the end of agglomerate

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1853

src/fvAgglomerationMethods/pairPatchAgglomeration/pairPatchAgglomeration.C

@@ -440,6 +440,8 @@ void Foam::pairPatchAgglomeration::agglomerate()
 
         nCoarseFacesOld = nCoarseFaces;
     }
+
+    compactLevels(nCreatedLevels);
 }