[LyX/master] Update fr.po

[jpc]

commit b7474e207efce21c791e752477c7d044097214aa
Author: jpc <jpc at lyx.org>
Date:   Mon Mar 29 10:24:06 2021 +0200

           Update fr.po

 po/fr.gmo |  Bin 620591 -> 622835 bytes
 po/fr.po  | 2405 ++++++++++++++++++++++++++++++++-----------------------------
 2 files changed, 1254 insertions(+), 1151 deletions(-)