kea: upgrade to v2.5.0

Changes:
Update license checksum: change in copyright year.
Update sha256sum for new version.

An additinal patch to fix the reproducible build failure.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>