Don't require a .dbconfig file on any masters.

masters/master.tryserver.libyuv/master.cfg

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # These modules come from scripts, which must be in the PYTHONPATH.
 from master import master_utils
 from master import slaves_list
 from master.builders_pools import BuildersPools
 from master.factory import annotator_factory
 from master.try_job_http import TryJobHTTP
 from master.try_mail_notifier import TryMailNotifier
 
 import config
 import master_site_config
 ActiveMaster = master_site_config.LibyuvTryServer
 
 MAIL_NOTIFIER = True
 LISTEN_TO_SVN = ActiveMaster.svn_url and ActiveMaster.is_production_host
 
 # This is the dictionary that the buildmaster pays attention to. We also use
 # a shorter alias to save typing.
 c = BuildmasterConfig = {}
 
-config.DatabaseSetup(c, require_dbconfig=ActiveMaster.is_production_host)
+config.DatabaseSetup(c)
 
 ####### CHANGESOURCES
 c['change_source'] = []
 
 # Avoid merging requests.
 c['mergeRequests'] = lambda *_: False
 
 ####### BUILDERS
 # Recipe based builders.
 specs = [
@@ skipping 132 matching lines @@
 # Must be at least 2x the number of slaves.
 c['eventHorizon'] = 100
 # Must be at least 2x the number of on-going builds.
 c['buildCacheSize'] = 100
 
 ####### PROJECT IDENTITY
 
 # The 'projectURL' string will be used to provide a link
 # from buildbot HTML pages to your project's home page.
 c['projectURL'] = 'http://dev.chromium.org/developers/testing/try-server-usage'