[autotest] fix one missing refactor to control_data.CONTROL_TYPE

This somehow slipped between the cracks in my previous refactor CL

BUG=chromium:240643
TEST=Unit tests.
DEPLOY=scheduler

Change-Id: Ic0f5110e965e38ec0253d6b18aed0576db175aba
Reviewed-on: https://gerrit.chromium.org/gerrit/51234
Reviewed-by: Alex Miller <milleral@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
diff --git a/scheduler/scheduler_models.py b/scheduler/scheduler_models.py
index d06107e..46109ad 100644
--- a/scheduler/scheduler_models.py
+++ b/scheduler/scheduler_models.py
@@ -26,6 +26,7 @@
 from autotest_lib.scheduler import drone_manager, email_manager
 from autotest_lib.scheduler import scheduler_config
 from autotest_lib.site_utils.graphite import stats
+from autotest_lib.client.common_lib import control_data
 
 _notify_email_statuses = []
 _base_url = None
@@ -865,7 +866,7 @@
 
 
     def is_server_job(self):
-        return self.control_type != 2
+        return self.control_type != control_data.CONTROL_TYPE.SERVER
 
 
     def tag(self):