Add a test for a broken config on startup

We currently log an exception and then exit, requiring operator
intervention.

Change-Id: I39f7a0fea7c59776d929718fb4116e62d23d25cc
diff --git a/tests/base.py b/tests/base.py
index 52c073f..ad72f12 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -1326,14 +1326,14 @@
         self.rpc = zuul.rpclistener.RPCListener(self.config, self.sched)
 
         self.sched.start()
-        self.sched.reconfigure(self.config)
-        self.sched.resume()
         self.webapp.start()
         self.rpc.start()
         self.launch_client.gearman.waitForServer()
-
         self.addCleanup(self.shutdown)
 
+        self.sched.reconfigure(self.config)
+        self.sched.resume()
+
     def tearDown(self):
         super(ZuulTestCase, self).tearDown()
         self.assertFinalState()