Fixing visuals for the SDN-IP demo.

Change-Id: I6f41e6cd72834ece28212de8b5962abaf2d418e4
diff --git a/web/gui/src/main/webapp/topo2.js b/web/gui/src/main/webapp/topo2.js
index 25782f9..81609e8 100644
--- a/web/gui/src/main/webapp/topo2.js
+++ b/web/gui/src/main/webapp/topo2.js
@@ -854,7 +854,7 @@
             var el = d3.select(this),
                 img;
 
-            $('<img src="img/host.png">').appendTo(el);
+            $('<img src="img/node.png">').appendTo(el);
             img = el.select('img')
                 .attr({
                     width: 30