Update gnupg to 2.2.7

Also, remove unnecessary USE_LDCONFIG.

• gpg: New option --no-symkey-cache to disable the passphrase cache for symmetrical en- and decryption.
• gpg: The ERRSIG status now prints the fingerprint if that is part of the signature.
• gpg: Relax emitting of FAILURE status lines
• gpg: Add a status flag to "sig" lines printed with --list-sigs.
• gpg: Fix "Too many open files" when using --multifile. [#3951]
• ssh: Return an error for unknown ssh-agent flags. [#3880]
• dirmngr: Fix a regression since 2.1.16 which caused corrupted CRL caches under Windows. [#2448,#3923]
• dirmngr: Fix a CNAME problem with pools and TLS. Also use a fixed mapping of keys.gnupg.net to sks-keyservers.net. [#3755]
• dirmngr: Try resurrecting dead hosts earlier (from 3 to 1.5 hours).
• dirmngr: Fallback to CRL if no default OCSP responder is configured.
• dirmngr: Implement CRL fetching via https. Here a redirection to http is explictly allowed.
• dirmngr: Make LDAP searching and CRL fetching work under Windows. This stopped working with 2.1. [#3937]
• agent,dirmngr: New sub-command "getenv" for "getinfo" to ease debugging.