Fix fixing sibling that can start fed job now

It was picking a higher weighted federation over lower weighted
federations because it had a earlier starttime. This shouldn't happen
because that's what the weights are for.

e.g.
will_run_resp for fed1: start:2016-10-13T15:19:47 sys_usage:0.00   weight:2
will_run_resp for fed2: start:2016-10-13T15:19:48 sys_usage:0.00   weight:1
will_run_resp for fed3: start:2016-10-13T15:19:48 sys_usage:0.00   weight:1
Earliest cluster:fed1 time:1476393587 now:1476393588
Submitted federated job 67119254 to fed1(self)