do not show empty categories in new/edit ticket categories list

[thekordy]

We should also filter our empty categories from the categories list drop down in

1. edit form
2. new ticket
3. make sure before update and store, you are not saving an empty category specially before firing trying to select agent

[thekordy]

Not necisserly any more, as an empty category will have only one option "Auto Select" which will assign tickets of empty categories to the admin

// If no agent is selected, select admin
        $selected_agent_id = config('ticketit.admin_ids')[0];

        foreach ($agents as $agent) {
            if ($count == 0) {
                $lowest_tickets = $agent->agentTickets->count();
                $selected_agent_id = $agent->id;
            }
            else {
                $tickets_count = $agent->agentTickets->count();
                if ($tickets_count < $lowest_tickets) {
                    $lowest_tickets = $tickets_count;
                    $selected_agent_id = $agent->id;
                }
            }
            $count++;
        }
        return $selected_agent_id;