define a default strategy for labels

Resources/config/admin_orm.xml

@@ -21,7 +21,7 @@
 
     <services>
         <service id="sonata.user.admin.user" class="%sonata.user.admin.user.class%">
-            <tag name="sonata.admin" manager_type="orm" group="%sonata.user.admin.groupname%" label="users" />
+            <tag name="sonata.admin" manager_type="orm" group="%sonata.user.admin.groupname%" label="users" label_translator_strategy="sonata.admin.label.strategy.underscore" />
             <argument />
             <argument>%sonata.user.admin.user.entity%</argument>
             <argument />
@@ -34,7 +34,7 @@
         </service>
 
         <service id="sonata.user.admin.group" class="%sonata.user.admin.group.class%">
-            <tag name="sonata.admin" manager_type="orm" group="%sonata.user.admin.groupname%" label="groups" />
+            <tag name="sonata.admin" manager_type="orm" group="%sonata.user.admin.groupname%" label="groups" label_translator_strategy="sonata.admin.label.strategy.underscore" />
             <argument />
             <argument>%sonata.user.admin.group.entity%</argument>
             <argument />