azureblob: work around SDK bug which causes errors for chunk-sized files
azureblob: work around SDK bug which causes errors for chunk-sized files

See https://github.com/Azure/azure-storage-blob-go/pull/75 for details

ncw/rclone,olihey/rclone,ncw/rclone,ncw/rclone,B4dM4n/rclone,B4dM4n/rclone,olihey/rclone,olihey/rclone,olihey/rclone,ncw/rclone,B4dM4n/rclone,B4dM4n/rclone