www/librespeed: Update to 5.2.5

Changes: https://github.com/librespeed/speedtest/releases/tag/5.2.5
Approved by: 0mp (mentor)
MFH: 2022Q1
Differential Revision: https://reviews.freebsd.org/D33737

(cherry picked from commit 62df9850ecd8e674aedbffd19e19cdb99aa4dbc2)