Correct blueprint topic links for modern Gerrit

The Gerrit query URL pattern has changed, so correct how we form it
in the update_blueprint hook to match expectations of current Gerrit
versions.

Change-Id: I368d0d30451051ab88a7b07dc6a2fbe7c4ddb886
diff --git a/jeepyb/cmd/update_blueprint.py b/jeepyb/cmd/update_blueprint.py
index 093e73b..97cf6b2 100644
--- a/jeepyb/cmd/update_blueprint.py
+++ b/jeepyb/cmd/update_blueprint.py
@@ -89,8 +89,8 @@
         wb = ''
     changed = False
     if topic:
-        topiclink = '%s/#q,topic:%s,n,z' % (link[:link.find('/', 8)],
-                                            topic)
+        topiclink = '%s/#/q/topic:%s' % (link[:link.find('/', 8)],
+                                         topic)
         if topiclink not in wb:
             wb += "\n\n\nGerrit topic: %(link)s" % dict(link=topiclink)
             changed = True