[FIX] When the routing has a location_id external the warehouse is NULL

This is logically correct, but the _get_rule overriden in subcontracted_service does the lookup of rule based on warehouse. If no warehouse set, fallback on product configured one.

i18n/es_AR.po

@@ -50,6 +50,12 @@ msgid "Operation Type"
 msgstr "Tipo de operación"
 
 #. module: emu_custom
+#: model:ir.model.fields,field_description:emu_custom.field_product_product_subcontracting_service_proc_rule_id
+#: model:ir.model.fields,field_description:emu_custom.field_product_template_subcontracting_service_proc_rule_id
+msgid "Subcontracting Service Procurement Rule"
+msgstr "Regla de subcontratación de servicio"
+
+#. module: emu_custom
 #: model:ir.model,name:emu_custom.model_product_template
 msgid "Product Template"
 msgstr "Plantilla de Producto"