small fix for deleting category if not present

app/controllers/admin/universal_tables_controller.rb

@@ -193,7 +193,7 @@ class Admin::UniversalTablesController < OrbitAdminController
 	def destroy
 		uid = params[:id].split("-").last
 		table = UTable.where(:uid => uid).first
-		table.category.destroy
+		table.category.destroy if !table.category.nil?
 		table.destroy
 		redirect_to admin_universal_tables_path
 	end