test: Remove impossible and commented test

This use case cannot happen with ArchiverWithRetentionPolicyDirector:
- If a row entry is referenced in the archiver db, it's present in
  the objstorage

- And if a row entry is not referenced in the archiver db, it
  won't be listed as missing since it's the archiver db which is
  read for listing the contents we want to archive.

swh/storage/tests/test_archiver.py

-# Copyright (C) 2015  The Software Heritage developers
+# Copyright (C) 2015-2017  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -300,24 +300,3 @@ class TestArchiver(DbsTestFixture, ServerTestFixture,
             len(self._get_backups(['uffizi'], ['banco', 's3'])),
             1
         )
-
-    # This cannot be tested with ArchiverWithRetentionPolicyDirector
-    # (it reads from archiver db)
-    # @istest
-    # def archive_missing_content__without_row_entry_in_archive_db(self):
-    #     """ Run archiver on a missing content should archive it.
-    #     """
-    #     obj_data = b'archive_missing_content_without_row_entry_in_archive_db'
-    #     obj_id = self._add_content('uffizi', obj_data)
-    #     # One entry in archiver db but no status about its whereabouts
-    #     # Content is actually missing on banco but present on uffizi
-    #     try:
-    #         self.dest_storage.get(obj_id)
-    #     except ObjNotFoundError:
-    #         pass
-    #     else:
-    #         self.fail('Content should not be present before archival')
-    #     self.archiver.run()
-    #     # now the content should be present on remote objstorage
-    #     remote_data = self.dest_storage.get(obj_id)
-    #     self.assertEquals(obj_data, remote_data)