python: Sort imports with isort.

Fixes #2665.

Regenerated by tabbott with `lint --fix` after a rebase and change in
parameters.

Note from tabbott: In a few cases, this converts technical debt in the
form of unsorted imports into different technical debt in the form of
our largest files having very long, ugly import sequences at the
start.  I expect this change will increase pressure for us to split
those files, which isn't a bad thing.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

scripts/lib/upgrade-zulip-from-git

@@ -1,18 +1,27 @@
 #!/usr/bin/env python3
-import os
-import sys
-import subprocess
-import logging
-import time
 import argparse
+import logging
+import os
+import subprocess
+import sys
+import time
 
 LOCAL_GIT_CACHE_DIR = '/srv/zulip.git'
 os.environ["PYTHONUNBUFFERED"] = "y"
 
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..'))
-from scripts.lib.zulip_tools import DEPLOYMENTS_DIR, make_deploy_path, \
-    get_deployment_lock, overwrite_symlink, release_deployment_lock, su_to_zulip, assert_running_as_root, \
-    get_config_file, get_deploy_options, get_config
+from scripts.lib.zulip_tools import (
+    DEPLOYMENTS_DIR,
+    assert_running_as_root,
+    get_config,
+    get_config_file,
+    get_deploy_options,
+    get_deployment_lock,
+    make_deploy_path,
+    overwrite_symlink,
+    release_deployment_lock,
+    su_to_zulip,
+)
 
 config_file = get_config_file()
 deploy_options = get_deploy_options(config_file)