Remove zerver/lib/query.py (dead code).

zerver/lib/query.py

@@ -1,18 +0,0 @@
-from __future__ import absolute_import
-
-from django.db.models.query import QuerySet
-from typing import TypeVar, List
-
-T = TypeVar('T')
-
-def last_n(n, query_set):
-    # type: (int, QuerySet[T]) -> List[T]
-    """Get the last n results from a Django QuerySet, in a semi-efficient way.
-       Returns a list."""
-
-    # We don't use reversed() because we would get a generator,
-    # which causes bool(last_n(...)) to be True always.
-
-    xs = list(query_set.reverse()[:n])
-    xs.reverse()
-    return xs

zerver/views/messages.py

@@ -22,7 +22,6 @@ from zerver.lib.actions import recipient_for_emails, do_update_message_flags, \
     create_mirror_user_if_needed, check_send_message, do_update_message, \
     extract_recipients, truncate_body
 from zerver.lib.cache import generic_bulk_cached_fetch
-from zerver.lib.query import last_n
 from zerver.lib.response import json_success, json_error
 from zerver.lib.utils import statsd
 from zerver.lib.validator import \