Remove advanced Zone SG check from the UI logic when creating L2 networks

Author: Dingane Hlaluku

ui/scripts/sharedFunctions.js

@@ -860,7 +860,7 @@ var addL2GuestNetwork = {
                             url: createURL('listZones'),
                             success: function(json) {
                                 var zones = $.grep(json.listzonesresponse.zone, function(zone) {
-                                    return (zone.networktype == 'Advanced' && zone.securitygroupsenabled != true); //Isolated networks can only be created in Advanced SG-disabled zone (but not in Basic zone nor Advanced SG-enabled zone)
+                                    return (zone.networktype == 'Advanced'); // L2 networks only available in Advanced Zones
                                 });
 
                                 args.response.success({