Fixed Undefined index error in XenResource_Listener_Proxy_ControllerFindNew

We're having an undefined index error show up in our logs a few times a day.

The resource with the id #1107 has been soft-deleted by its creator, so I'm guessing this is an issue with unregistered users being unable to view deleted resources.

I've applied a guard within the for loop to prevent the error from being thrown, but hopefully this can be properly fixed in the next release.