Remove use of portal_properties in context navigation.

Theoretically we checked `portal_properties.site_properties.sortAttribute`.

news/125.bugfix

@@ -0,0 +1,3 @@
+Remove use of `portal_properties` in context navigation.
+Theoretically we checked `portal_properties.site_properties.sortAttribute`.
+[maurits]

src/plone/restapi/services/contextnavigation/get.py

@@ -625,9 +625,6 @@ def __init__(self, context, data):
         self.context = context
         self.data = data
 
-        portal_properties = getToolByName(context, "portal_properties")
-        navtree_properties = getattr(portal_properties, "navtree_properties")
-
         # Acquire a custom nav query if available
         customQuery = getattr(context, "getCustomNavQuery", None)
         if customQuery is not None and safe_callable(customQuery):
@@ -668,14 +665,6 @@ def __init__(self, context, data):
         # Only list the applicable types
         query["portal_type"] = typesToList(context)
 
-        # Apply the desired sort
-        sortAttribute = navtree_properties.getProperty("sortAttribute", None)
-        if sortAttribute is not None:
-            query["sort_on"] = sortAttribute
-            sortOrder = navtree_properties.getProperty("sortOrder", None)
-            if sortOrder is not None:
-                query["sort_order"] = sortOrder
-
         # Filter on workflow states, if enabled
         registry = getUtility(IRegistry)
         navigation_settings = registry.forInterface(INavigationSchema, prefix="plone")