add list.label_groups to german translation

Resources/translations/SonataUserBundle.de.xliff

@@ -118,6 +118,10 @@
                 <source>list.label_email</source>
                 <target>E-Mail-Adresse</target>
             </trans-unit>
+            <trans-unit id="list.label_groups">
+                <source>list.label_groups</source>
+                <target>Gruppen</target>
+            </trans-unit>
             <trans-unit id="list.label_locked">
                 <source>list.label_locked</source>
                 <target>Gesperrt</target>