Move logger app to included_applications

We don't particularly need this to start with ejabberd, and by having
it always started we will change logger to always use elixir formating.

mix.exs

@@ -43,11 +43,11 @@ defmodule Ejabberd.MixProject do
 
   def application do
     [mod: {:ejabberd_app, []},
-     applications: [:idna, :inets, :kernel, :sasl, :ssl, :stdlib, :mix, :logger,
+     applications: [:idna, :inets, :kernel, :sasl, :ssl, :stdlib, :mix,
                     :fast_tls, :fast_xml, :fast_yaml, :jose,
                     :p1_utils, :stringprep, :syntax_tools, :yconf, :xmpp]
      ++ cond_apps(),
-     included_applications: [:mnesia, :os_mon,
+     included_applications: [:mnesia, :os_mon, :logger,
                              :cache_tab, :eimp, :mqtree, :p1_acme,
                              :p1_oauth2, :pkix]
      ++ cond_included_apps()]