Fix test_live_configuration

This test, which is currently passing, lacked a pause which could
cause it to erroneously pass even when broken.  Update the test
to include it.

Change-Id: Ic4391d4a80489daaffdcff2f2012f3a252dbc0db
diff --git a/tests/unit/test_scheduler.py b/tests/unit/test_scheduler.py
index 42e8687..17e0cdb 100755
--- a/tests/unit/test_scheduler.py
+++ b/tests/unit/test_scheduler.py
@@ -2395,6 +2395,7 @@
         self.waitUntilSettled()
 
         self.sched.reconfigure(self.config)
+        self.waitUntilSettled()
 
         self.launch_server.hold_jobs_in_build = False
         self.launch_server.release()