Update gnupg to 2.2.15

• sm: Fix --logger-fd and --status-fd on Windows for non-standard file descriptors.
• sm: Allow decryption even if expired keys are configured. [#4431]
• agent: Change command KEYINFO to print ssh fingerprints with other hash algos.
• dirmngr: Fix build problems on Solaris due to the use of reserved symbol names. [#4420]
• wkd: New commands --print-wkd-hash and --print-wkd-url for gpg-wks-client.
  
  Release-info: https://dev.gnupg.org/T4434