stable tree timer

templates/buildbot/master.cfg.j2

@@ -54,7 +54,7 @@ c['builders'].append(
 c['schedulers'].append(schedulers.SingleBranchScheduler(
                             name="{{builder_name}}",
                             change_filter=util.ChangeFilter(branch='master'),
-                            treeStableTimer=None,
+                            treeStableTimer=5,
                             builderNames=['{{builder_name}}']))
 
 {% endfor %}