Security update for python-python-gnupg (moderate)

This update for python-python-gnupg to version 0.4.3 fixes the following
issues:

The following security vulnerabilities were addressed:

 - Sanitize diagnostic output of the original file name in verbose mode
   (CVE-2018-12020 boo#1096745)

The following other changes were made:

 - Add --no-verbose to the gpg command line, in case verbose is specified
   is gpg.conf.
 - Add expect_passphrase password for use on GnuPG >= 2.1 when passing
   passphrase to gpg via pinentry
 - Provide a trust_keys method to allow setting the trust level for keys
 - When the gpg executable is not found, note the path used in the
   exception message
 - Make error messages more informational