security/p5-Crypt-OpenPGP: update to 1.15

Full changelog: https://metacpan.org/dist/Crypt-OpenPGP/changes

Since 1.13 upsrtream project has a new maintainer working in merge
past PRs.

[Changes since 1.12]

• Release of TRIAL 1.14 as production
• PR #15 - (@nielslaukens) Added UserAttribute class (unparsed)
• PR #16 - (@nielslaukens) Bugfix: allow multiple 'Preferred hash/compression algorithms'
• PR #17 - (@nielslaukens) Added UserAttribute class (unparsed)
• PR #18 - (@nielslaukens) Bugfix: parse notation data subpacket of Signature correctly
• PR #19 - (@nielslaukens) Support unknown algos
• Closed RT#53323: Failing on 64bit machines
• Fix RT#123452 Require at least one Random Source
• GH PR#29 (@andyjack) Add use strict to increase kwalitee
• GH PR#31 (@gozer) ElGamal: key's p can be a large integer, use Bigint
• GH PR#32 (@Shildus). Add support for SHA-2 (SHA-512, SHA-256,...) signatures verification

Port changes:

• Add new dependency to make perl test pass.