Tweak ssh-keyscan timing
Tweak ssh-keyscan timing

Make the call itself timeout after 1s instead of 5s. Make update_lock()
try 15 times, sleeping for 1s between attempts. A full timeout of
update_lock() should take ~30s.

Signed-off-by: Zack Cerza <d7cdf09fc0f0426e98c9978ee42da5d61fa54986@redhat.com>

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