set server name

templates/buildbot/master.cfg.j2

@@ -90,7 +90,7 @@ c['titleURL'] = "https://buildbot.github.io/hello-world/"
 # the 'www' entry below, but with an externally-visible host name which the
 # buildbot cannot figure out without some help.
 
-c['buildbotURL'] = "http://localhost:8010/"
+c['buildbotURL'] = "https://{{buildbot_server_name}}/"
 
 # minimalistic config to activate new web UI
 c['www'] = dict(port=8010,