s3tests: fix typo
s3tests: fix typo

SUSE/teuthology,michaelsevilla/teuthology,ceph/teuthology,ivotron/teuthology,dreamhost/teuthology,michaelsevilla/teuthology,caibo2014/teuthology,SUSE/teuthology,yghannam/teuthology,yghannam/teuthology,ktdreyer/teuthology,zhouyuan/teuthology,robbat2/teuthology,dmick/teuthology,tchaikov/teuthology,dmick/teuthology,t-miyamae/teuthology,dmick/teuthology,ceph/teuthology,SUSE/teuthology,dreamhost/teuthology,ivotron/teuthology,ktdreyer/teuthology,tchaikov/teuthology,caibo2014/teuthology,robbat2/teuthology,zhouyuan/teuthology,t-miyamae/teuthology