fix typo in events.clj

src/metabase/events.clj

@@ -76,7 +76,7 @@
   channel)
 
 (defn subscribe-to-topics
-  "Convenience method for subscribing to series of topics against a single channel."
+  "Convenience method for subscribing to a series of topics against a single channel."
   [topics channel]
   {:pre [(coll? topics)]}
   (loop [[topic & rest] (vec topics)]