[glcient] Delete unused import
Change-Id: I6f2b22a561e823455f5e1af26a88ed7d8c0a896d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6444535
Commit-Queue: Allen Li <ayatane@chromium.org>
Reviewed-by: Gavin Mak <gavinmak@google.com>