nat: "users" dump for ED-NAT

Since the removal of "users" concept in ED-NAT nat44_user_dump API
returns empty array. This brings back previous behaviour at
a considerable runtime cost until a better API is introduced.

Type: improvement
Change-Id: I5a45923cfeb6b8ebe6fc906601264d6567386991
Signed-off-by: Klement Sekera <ksekera@cisco.com>
diff --git a/test/requirements-3.txt b/test/requirements-3.txt
index a32dc6e..a77c089 100644
--- a/test/requirements-3.txt
+++ b/test/requirements-3.txt
@@ -258,4 +258,4 @@
 
 # WARNING: The following packages were not pinned, but pip requires them to be
 # pinned when the requirements file includes hashes. Consider using the --allow-unsafe flag.
-# setuptools==46.1.3        # via sphinx
+# setuptools==46.2.0        # via sphinx