refactor valid_enum

tests/flattener_dicos/80empty_valid_enum/00-base.xml

@@ -0,0 +1,20 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<rougail>
+
+    <services/>
+
+    <variables>
+        <family name="general">
+            <variable name="mode_conteneur_actif" type="string" description="No change"/>
+        </family>
+    </variables>
+
+    <constraints>
+        <check name="valid_enum" target="mode_conteneur_actif"/>
+    </constraints>
+
+    <help/>
+
+</rougail>
+<!-- vim: ts=4 sw=4 expandtab
+-->