[LyX/master] Update fr.po (step 1)

[jpc]

commit 29bde6e64aa873d3dbb1ebb055c05b11331ca83c
Author: jpc <jpc at lyx.org>
Date:   Tue Feb 9 18:38:56 2021 +0100

        Update fr.po (step 1)

 po/fr.gmo |  Bin 572258 -> 581752 bytes
 po/fr.po  | 1447 ++++++++++++++++++++++++++++++++-----------------------------
 2 files changed, 763 insertions(+), 684 deletions(-)