python: Fix test.

* lang/python/tests/t-quick-key-manipulation.py: Modify the
configuration file in the ephemeral home directory, not the one used
by all the tests.

Fixes-commit: 15fbac9e72
Signed-off-by: Justus Winter <justus@g10code.com>

lang/python/tests/t-quick-key-manipulation.py

@@ -20,6 +20,7 @@
 from __future__ import absolute_import, print_function, unicode_literals
 del absolute_import, print_function, unicode_literals
 
+import os
 import gpg
 
 import support
@@ -92,7 +93,7 @@ with support.EphemeralContext() as ctx:
         pass
 
     # Check setting the TOFU policy.
-    with open("gpg.conf", "a") as handle:
+    with open(os.path.join(ctx.home_dir, "gpg.conf"), "a") as handle:
         handle.write("trust-model tofu+pgp\n")
 
     for name, policy in [(name, getattr(gpg.constants.tofu.policy, name))