[LyX/master] Update it.po

[Enrico Forestieri]

commit a569aeaf66fc6b4d041c713709450701791deac2
Author: Enrico Forestieri <for...@lyx.org>
Date:   Tue Oct 2 21:35:06 2018 +0200

    Update it.po

 po/it.gmo |  Bin 546344 -> 555109 bytes
 po/it.po  | 3513 +++++++++++++++++++++++++++++++++++--------------------------
 2 files changed, 2039 insertions(+), 1474 deletions(-)