Amend recent commits: lists:append is preferable for 1-level deep lists

See
https://www.erlang.org/doc/system/listhandling.html#deep-and-flat-lists

src/ejabberd_http.erl

@@ -934,7 +934,7 @@ find_handler_port_path(Tls, Handler) ->
          (_) ->
               []
       end, ets:tab2list(ejabberd_listener)),
-    lists:flatten(Paths).
+    lists:append(Paths).
 
 find_handler_port_path_option(ThisTls, Port, Handler, Handlers) ->
     lists:filtermap(fun({Path, H}) when H == Handler ->

src/ejabberd_web_admin.erl

@@ -2017,7 +2017,7 @@ nice_this(This) when is_atom(This) ->
 nice_this(This) when is_binary(This) ->
     nice_this(binary_to_list(This));
 nice_this(This) when is_list(This) ->
-    list_to_binary(lists:flatten([string:titlecase(Word)
+    list_to_binary(lists:append([string:titlecase(Word)
                                   || Word <- string:replace(This, "_", " ", all)])).
 
 -spec long_this(These :: [This :: atom()]) -> Long :: binary().