Fix wrong assignment in the mochiweb parser

Erlang does not allow rebindings.

Closes #492

src/floki_mochi_html.erl

@@ -254,16 +254,16 @@ tree([{doctype, _} | Rest], Stack, Opts) ->
     tree(Rest, Stack, Opts).
 
 norm({Tag, Attrs}, Opts) ->
-    Attrs = [{norm(K, Opts), iolist_to_binary(V)} || {K, V} <- Attrs],
+    Attrs0 = [{norm(K, Opts), iolist_to_binary(V)} || {K, V} <- Attrs],
     case lists:keyfind(attributes_as_maps, 1, Opts) of
         {attributes_as_maps, true} ->
             % The HTML specs says we should ignore duplicated attributes and keep the first
             % occurence of a given key.
             % Since `maps:from_list/1` does the opposite, we need to reverse the attributes.
             % See https://github.com/philss/floki/pull/467#discussion_r1225548333
-            {norm(Tag, Opts), maps:from_list(lists:reverse(Attrs)), []};
+            {norm(Tag, Opts), maps:from_list(lists:reverse(Attrs0)), []};
         _ ->
-            {norm(Tag, Opts), Attrs, []}
+            {norm(Tag, Opts), Attrs0, []}
     end;
 norm(Tag, _Opts) when is_binary(Tag) ->
     Tag;