Fix socket connectivity on production.

Fix unused variable warnings.

ui/lib/ui_web/channels/morse_progress_channel.ex

@@ -1,7 +1,7 @@
 defmodule UiWeb.MorseProgressChannel do
   use UiWeb, :channel
 
-  def join(channel_name, _params, socket) do
+  def join(_channel_name, _params, socket) do
     {:ok, %{hi: :there}, socket}
   end
 end