pylint: remove unused imports

Removed unused imports accross multiple files.

Change-Id: Ib5ae4cebf9660e7339b11e3fa592d99f8d51e8d8
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/354700
Tested-by: Daniel Kutik <daniel.kutik@lavawerk.com>
Reviewed-by: Mike Frysinger <vapier@google.com>
diff --git a/manifest_xml.py b/manifest_xml.py
index 129eb3f..5b83f36 100644
--- a/manifest_xml.py
+++ b/manifest_xml.py
@@ -22,7 +22,7 @@
 import urllib.parse
 
 import gitc_utils
-from git_config import GitConfig, IsId
+from git_config import GitConfig
 from git_refs import R_HEADS, HEAD
 from git_superproject import Superproject
 import platform_utils