Pick a random bucket name when probing for signature version (#2491)
Pick a random bucket name when probing for signature version (#2491)

Probing buckets is a mechanism used to automatically detect supported
S3 signature version. However, it seems that probe-bucket-sign is already
used by someone, the thing that makes probing fails with 403 error. This
PR changes the code to pick a random bucket name when probing.
vadmeste/mc,krisis/mc,vadmeste/mc,minio/mc,krisis/mc,minio/mc,balamurugana/mc,balamurugana/mc