test: known broken test for list(db.config) in python-cffi bindings

As of notmuch 0.34.2 [1], the python-cffi bindings make available the
configuration from both a config file and the database when accessing
Database.config like a dictionary.  It is therefore confusing that the
iterator operations only work on the configuration information stored
in the database.

[1]: d7f9572413

test/T055-path-config.sh

@@ -293,6 +293,27 @@ user.primary_email=test_suite@notmuchmail.org
 EOF
    test_expect_equal_file EXPECTED OUTPUT
 
+   test_begin_subtest "Config list from python ($config)"
+   test_subtest_known_broken
+   test_python <<EOF > OUTPUT
+from notmuch2 import Database
+db=Database(config=Database.CONFIG.SEARCH)
+for key in list(db.config):
+    print(key)
+EOF
+   cat <<EOF > EXPECTED
+database.autocommit
+database.backup_dir
+database.hook_dir
+database.mail_root
+database.path
+maildir.synchronize_flags
+new.tags
+user.name
+user.other_email
+user.primary_email
+EOF
+   test_expect_equal_file EXPECTED OUTPUT
    case $config in
        XDG*)
 	   test_begin_subtest "Set shadowed config value in database ($config)"