Topo2: unpin nodes when a node is hovered and 'U' us pressed

Change-Id: I5f25243073ea7e32354c4777576ad402e6124296
diff --git a/web/gui/src/main/webapp/app/view/topo2/topo2Device.js b/web/gui/src/main/webapp/app/view/topo2/topo2Device.js
index ddb9b55..823387c 100644
--- a/web/gui/src/main/webapp/app/view/topo2/topo2Device.js
+++ b/web/gui/src/main/webapp/app/view/topo2/topo2Device.js
@@ -74,6 +74,7 @@
                     },
                     onClick: function () {
 
+                        if (d3.event.defaultPrevented) return;
                         var selected = this.select(d3.event);
 
                         if (_.isArray(selected) && selected.length > 0) {