Fixed case where chacl command incorrectly recognizes an email address as a domain
Fixed case where chacl command incorrectly recognizes an email address as a domain

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