Fix test failure of test_XXX caused by upgrade of gpgme from 1.6.0 to
1.8.0:

======================================================================
FAIL: test_encrypt_to_signonly (tests.test_encrypt_decrypt.EncryptDecryptTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/tmp/guix-build-python2-pygpgme-0.3.drv-0/pygpgme-0.3/tests/test_encrypt_decrypt.py", line 185, in test_encrypt_to_signonly
    self.assertEqual(exc.args[0], gpgme.ERR_SOURCE_UNKNOWN)
AssertionError: 7 != 0

----------------------------------------------------------------------

Patch copied from the Debian package pygpgme-0.3-1.2:

https://sources.debian.net/src/pygpgme/0.3-1.2/debian/patches/0005-Fix-test-failures-with-pinentry.patch/

From: "Dr. Tobias Quathamer" <toddy@debian.org>
Date: Thu, 24 Nov 2016 12:20:54 +0100
Subject: Fix test failures with pinent</td></tr></table>
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