chore(authn): insert final newline

apps/emqx/src/emqx_authentication_sup.erl

@@ -45,4 +45,4 @@ init([]) ->
               type => worker,
               modules => [emqx_authentication]},
 
-    {ok, {SupFlags, [AuthN]}}.
+    {ok, {SupFlags, [AuthN]}}.