[autotest] temporarily disable suite timeline report

Temporarily disable the suite timeline report to test whether it causes
the load on master db.

BUG=chromium:695287
TEST=None

Change-Id: I8b58b17b8f0923dd6d4c663e79fd163662009d5b
Reviewed-on: https://chromium-review.googlesource.com/446897
Tested-by: Shuqian Zhao <shuqianz@chromium.org>
Trybot-Ready: Shuqian Zhao <shuqianz@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Commit-Queue: Shuqian Zhao <shuqianz@chromium.org>
diff --git a/scheduler/postjob_task.py b/scheduler/postjob_task.py
index 67733f5..b13604d 100644
--- a/scheduler/postjob_task.py
+++ b/scheduler/postjob_task.py
@@ -318,7 +318,7 @@
 
     def _generate_command(self, results_dir):
         return [_parser_path, '--write-pidfile', '--record-duration',
-                '--suite-report', '-l', '2', '-r', '-o', results_dir]
+                '-l', '2', '-r', '-o', results_dir]
 
 
     @property