Fix slave_hosts_cfg test
Fix slave_hosts_cfg test

TBR=kjlubick
BUG=skia:

Review URL: https://codereview.chromium.org/1823383004

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot