Fix two Metalink tests if $HOME is changed

* conf/expected_files.py (gen_local_fs_snapshot): Skip processing
  of 'pubring.kbx'

testenv/conf/expected_files.py

@@ -24,6 +24,11 @@ class ExpectedFiles:
         snapshot = {}
         for parent, dirs, files in os.walk('.'):
             for name in files:
+                # pubring.kbx will be created by libgpgme if $HOME doesn't contain the .gnupg directory.
+					 # setting $HOME to CWD (in base_test.py) breaks two Metalink tests, so we skip this file here.
+                if name == 'pubring.kbx':
+                    continue
+
                 f = {'content': ''}
                 file_path = os.path.join(parent, name)
                 with open(file_path) as fp: