Remove unused import.
Remove unused import.

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