// display_header/footer = false will display <head> tags

admin-dev/themes/template/layout.tpl

@@ -23,9 +23,7 @@
 *  @license    http://opensource.org/licenses/afl-3.0.php  Academic Free License (AFL 3.0)
 *  International Registered Trademark & Property of PrestaShop SA
 *}
-{if $display_header}
-	{include file='header.tpl'}
-{/if}
+{include file='header.tpl'}
 {if isset($conf)}
 	<div class="conf">
 		<img src="../img/admin/ok2.png" alt="" />{$conf}
@@ -115,6 +113,4 @@
 {/if}
 
 {$page}
-{if $display_footer}
-	{include file='footer.tpl'}
-{/if}
+{include file='footer.tpl'}