www/lightsquid: prolong datestamp check up to 2100

lightparser.pl stops processing data at the beginning of 2021 due to a
hardcoded stop date. This patch substitutes 2100 for 2020.

Reported by: Oleg Streejak <oleg@pcbtech.ru>
PR: 254382
MFH: 2026Q2
Event: Wiesbaden Hackathon 202604

(cherry picked from commit 91d2c00565533e426305b21c2f1fae5ab59eec3d)