Remove unnecessary kruft

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

lib/irc/irc.ex

@@ -71,12 +71,6 @@ defmodule Omnibot.Irc do
     {:noreply, socket}
   end
 
-  @impl true
-  def handle_cast({:tcp, line}, socket) do
-    Logger.debug(line)
-    {:noreply, socket}
-  end
-
   @impl true
   def handle_info({:tcp, _socket, line}, socket) do
     Logger.debug(String.trim(line))