remove trailing comma from cluster strategy tests (see #950)

tests/Strategy/Cluster.html

@@ -45,7 +45,7 @@
         var map = new OpenLayers.Map('map', {
             resolutions: [4, 2, 1],
             maxExtent: new OpenLayers.Bounds(-40, -40, 40, 40),
-            zoomMethod: null,
+            zoomMethod: null
         });
         map.addLayer(layer);