Only have one subscription per callback.

config/config.exs

@@ -30,6 +30,8 @@ config :mime, :types, %{
   "application/xrd+xml" => ["xrd+xml"]
 }
 
+config :pleroma, :websub_verifier, Pleroma.Web.Websub
+
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.
 import_config "#{Mix.env}.exs"

config/test.exs

@@ -24,3 +24,5 @@ config :pleroma, Pleroma.Repo,
 
 # Reduce hash rounds for testing
 config :comeonin, :pbkdf2_rounds, 1
+
+config :pleroma, :websub_verifier, Pleroma.Web.WebsubMock