document must be set modified when range name is defined, fdo#79451

Change-Id: I382bef9b95d40a1abac993795e8da540b5aa5d18
(cherry picked from commit 1c8babfdb0808318bbaa94e911c819456a65337e)
Reviewed-on: https://gerrit.libreoffice.org/9804
Reviewed-by: Muthu Subramanian K <muthusuba@gmail.com>
Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>