Avoid unnecessarily validating buckets in boto_translation
Avoid unnecessarily validating buckets in boto_translation

This fixes an access error when interacting with S3
user-specific directories, per
https://github.com/GoogleCloudPlatform/gsutil/issues/366

GoogleCloudPlatform/gsutil,BrandonY/gsutil,GoogleCloudPlatform/gsutil,fishjord/gsutil