Use new demo GeoServer location

demo.opengeo.org currently redirects to demo.boundlessgeo.com, so this
change makes it so the new location is used directly.

examples/vector-wfs.js

@@ -13,7 +13,7 @@ goog.require('ol.tilegrid.XYZ');
 var vectorSource = new ol.source.ServerVector({
   format: new ol.format.GeoJSON(),
   loader: function(extent, resolution, projection) {
-    var url = 'http://demo.opengeo.org/geoserver/wfs?service=WFS&' +
+    var url = 'http://demo.boundlessgeo.com/geoserver/wfs?service=WFS&' +
         'version=1.1.0&request=GetFeature&typename=osm:water_areas&' +
         'outputFormat=text/javascript&format_options=callback:loadFeatures' +
         '&srsname=EPSG:3857&bbox=' + extent.join(',') + ',EPSG:3857';