Fix python error when removing non-existent object named /
Fix python error when removing non-existent object named /

dtjackson/gsutil,fishjord/gsutil,dimfeld/gsutil,ttiurani/gsutil,mattdr/gsutil,chriskuehl/gsutil-debian,craigcitro/gsutil,GoogleCloudPlatform/gsutil,GoogleCloudPlatform/gsutil,BrandonY/gsutil