[FIX] l10n_es_pos: compatibility with kitcheb order printers

As we use the simplified invoice ref, the internal reference is usually
useless. But when a kitchen order is printed that's the only reference
we've got. This way we can show that reference in the ticket only when
kitchen printers are configured in the point of sale.

TT52521

l10n_es_pos/static/src/xml/pos.xml

@@ -58,7 +58,7 @@
         >
             <attribute
                 name="t-if"
-            >!env.pos.config.is_simplified_config or receipt.is_to_invoice</attribute>
+            >!env.pos.config.is_simplified_config or receipt.is_to_invoice or env.pos.config.iface_printers</attribute>
         </xpath>
     </t>
 </templates>