fix(elixir): do not start logger before config

Despite Hocon generating the same config in both Elixir and Erlang
releases, apparently starting Logger before other applications has the
subtle effect of redirecting all logs to `log/erlang.log.N`, even
those lines that should appear in `log/emqx.log.N`.  Simply not adding
it to the application list restores the Erlang release behavior.

mix.exs

@@ -154,7 +154,6 @@ defmodule EMQXUmbrella.MixProject do
 
   def applications(release_type) do
     [
-      logger: :permanent,
       crypto: :permanent,
       public_key: :permanent,
       asn1: :permanent,