Skip multiconfig test when running S3 tests
Skip multiconfig test when running S3 tests

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