Removed ZGB machines. They dont longer exist in the lab.

BUG=None
TEST=None

Change-Id: Id6bdf17551552cfe9e04a89d8b76547959cfac3f
Reviewed-on: https://chrome-internal-review.googlesource.com/193701
Commit-Queue: Luis Lozano <llozano@chromium.org>
Tested-by: Luis Lozano <llozano@chromium.org>
Reviewed-by: Caroline Tice <cmtice@google.com>
diff --git a/crosperf/default_remotes b/crosperf/default_remotes
index 393e81a..5967041 100644
--- a/crosperf/default_remotes
+++ b/crosperf/default_remotes
@@ -1,4 +1,3 @@
-x86-zgb  : chromeos1-rack3-host4.cros chromeos1-rack3-host5.cros chromeos1-rack3-host6.cros
 x86-alex : chromeos2-row1-rack4-host7.cros chromeos2-row1-rack4-host8.cros chromeos2-row1-rack4-host9.cros
 lumpy    : chromeos2-row2-rack4-host10.cros chromeos2-row2-rack4-host11.cros chromeos2-row2-rack4-host12.cros
 stumpy   : chromeos2-row3-rack7-host1.cros chromeos2-row3-rack7-host2.cros chromeos2-row3-rack7-host3.cros