Fix style errors.

dulwich/client.py

@@ -52,7 +52,6 @@ from urllib.parse import (
     unquote as urlunquote,
     urlparse,
     urljoin,
-    urlunparse,
     urlunsplit,
     urlunparse,
     )

dulwich/ignore.py

@@ -24,7 +24,6 @@ For details for the matching rules, see https://git-scm.com/docs/gitignore
 
 import os.path
 import re
-import sys
 
 from dulwich.config import get_xdg_config_home_path
 

dulwich/refs.py

@@ -24,7 +24,6 @@
 """
 import errno
 import os
-import sys
 
 from dulwich.errors import (
     PackedRefsException,

dulwich/tests/test_repository.py

@@ -362,7 +362,8 @@ class RepositoryRootTests(TestCase):
             encoded_path = r.path
             if not isinstance(encoded_path, bytes):
                 encoded_path = os.fsencode(encoded_path)
-            self.assertEqual(encoded_path, c.get((b'remote', b'origin'), b'url'))
+            self.assertEqual(
+                encoded_path, c.get((b'remote', b'origin'), b'url'))
             self.assertEqual(
                 b'+refs/heads/*:refs/remotes/origin/*',
                 c.get((b'remote', b'origin'), b'fetch'))