autotest: remove dependencies of suite_scheduler.

BUG=chromium:793179
TEST=Ran unittest.

Change-Id: I633a1ec2ccc352abd4da20c8b7667b0eb6d3305e
Reviewed-on: https://chromium-review.googlesource.com/816080
Commit-Ready: Xixuan Wu <[email protected]>
Tested-by: Xixuan Wu <[email protected]>
Reviewed-by: Dan Shi <[email protected]>
diff --git a/scheduler/rdb_hosts.py b/scheduler/rdb_hosts.py
index 67da93f..2eb9477 100644
--- a/scheduler/rdb_hosts.py
+++ b/scheduler/rdb_hosts.py
@@ -26,7 +26,7 @@
 from autotest_lib.frontend.afe import models as afe_models
 from autotest_lib.scheduler import rdb_requests
 from autotest_lib.scheduler import rdb_utils
-from autotest_lib.site_utils.suite_scheduler import constants
+from autotest_lib.server import constants
 from autotest_lib.utils import labellib
 
 try: