Update sync_thunderbird.rst

update internal reference

Signed-off-by: tflidd <[email protected]>

user_manual/groupware/sync_thunderbird.rst

@@ -22,7 +22,7 @@ Contacts
 
 If you later want to add a new address book, you can redo all of those steps and only the books not already synchronized will be suggested.
 
-.. note:: If your account uses two-factor authentication, you need a `dedicated app password <../session_management.html#managing-devices>`_ for login rather than your
+.. note:: If your account uses two-factor authentication, you need a :ref:`dedicated app password <#managing_devices>` for login rather than your
    regular password.
 
 Calendars