fix(emqx_resource_api): remove unused module

apps/emqx_resource/src/emqx_resource_api.erl

@@ -1,23 +0,0 @@
-%%--------------------------------------------------------------------
-%% Copyright (c) 2020-2022 EMQ Technologies Co., Ltd. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%%     http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%--------------------------------------------------------------------
--module(emqx_resource_api).
-
--export([stringify/1]).
-
-stringify(Bin) when is_binary(Bin) -> Bin;
-stringify(Str) when is_list(Str) -> list_to_binary(Str);
-stringify(Reason) ->
-    iolist_to_binary(io_lib:format("~p", [Reason])).