portals-list: filter out portal without real data (bug in intel)

Portals with empty title causes exception when sorting
Anyway, table rows filled with <undefined> are not useful

plugins/portals-list.user.js

@@ -154,6 +154,14 @@ window.plugin.portalslist.getPortals = function() {
     // eliminate offscreen portals (selected, and in padding)
     if(!displayBounds.contains(portal.getLatLng())) return true;
 
+    if (!portal.options.data.title) { // no data about portal
+      // bug in intel, observed with ghost fields
+      // todo: check if such portal is really duplicate
+      // otherwise better keep it (with data filled by some defaults)
+      console.warn('filtering out "ghost" portal:', portal.options.data);
+      return true;
+    }
+
     retval=true;
 
     switch (portal.options.team) {