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/topo2Select.js b/web/gui/src/main/webapp/app/view/topo2/topo2Select.js
index ad99749..242d55a0 100644
--- a/web/gui/src/main/webapp/app/view/topo2/topo2Select.js
+++ b/web/gui/src/main/webapp/app/view/topo2/topo2Select.js
@@ -122,7 +122,11 @@
             return mdist(p, m) <= proximity;
         }
 
-        var links = t2rs.regionLinks();
+        var links = [];
+
+        if (t2rs.model.get('links')) {
+            links = (t2rs.backgroundRendered) ? t2rs.regionLinks() : [];
+        }
 
         if (links.length) {
             minDist = proximity * 2;