When user's data are empty, dialog shows "(no name set)".

Dialog:
Writer->File->Versions...->Save New Version

Change-Id: I6780cbe452fbc206b3e153975dbb1c1d9570718b
Reviewed-on: https://gerrit.libreoffice.org/12307Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>