rename example worker to local worker

templates/buildbot/master.cfg.j2

@@ -15,7 +15,7 @@ c = BuildmasterConfig = {}
 # The 'workers' list defines the set of recognized workers. Each element is
 # a Worker object, specifying a unique worker name and password.  The same
 # worker name and password must be configured on the worker.
-c['workers'] = [worker.LocalWorker("example-worker")]
+c['workers'] = [worker.LocalWorker("local-worker")]
 
 # 'protocols' contains information about protocols which master will use for
 # communicating with workers. You must define at least 'port' option that workers