small fix for deleted users

app/views/admin/tickets/_ticket.html.erb

@@ -35,8 +35,8 @@
     <% if !ticket.taken_by.nil? %>
       <span class="ticket-author label label-primary">
         <i class="icon-user"></i> 
-        <% user = User.find(ticket.taken_by) %>
-         <%= user.name if !user.nil? %>
+        <% user = User.find(ticket.taken_by) rescue nil %>
+         <%= !user.nil? ? user.name : "User Deleted" %>
       </span>
     <% end %>
 	</div>