Update SonataAdminBundle.pl.xliff

Resources/translations/SonataAdminBundle.pl.xliff

@@ -404,7 +404,7 @@
             </trans-unit>
             <trans-unit id="message_form_group_empty">
                 <source>message_form_group_empty</source>
-                <target>message_form_group_empty</target>
+                <target>Brak dostępnych pól.</target>
             </trans-unit>
         </body>
     </file>