gnupg2 2.0.25

Update to latest stable release, update patch.
gpg-agent 2.0.25

Update to latest stable release, update patch.
gnupg2: use npth instead of pth

Use the newer npth library that GnuPG has migrated to.

Closes #30580.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>