websocket: removed deprecated API "esp_websocket_client_send"

Closes IDF-1470


* Original commit: espressif/esp-idf@7f6ab93f7e

components/esp_websocket_client/include/esp_websocket_client.h

@@ -1,16 +1,8 @@
-// Copyright 2015-2018 Espressif Systems (Shanghai) PTE LTD
-//
-// 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.
+/*
+ * SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
 
 #ifndef _ESP_WEBSOCKET_CLIENT_H_
 #define _ESP_WEBSOCKET_CLIENT_H_
@@ -169,20 +161,6 @@ esp_err_t esp_websocket_client_stop(esp_websocket_client_handle_t client);
  */
 esp_err_t esp_websocket_client_destroy(esp_websocket_client_handle_t client);
 
-/**
- * @brief      Generic write data to the WebSocket connection; defaults to binary send
- *
- * @param[in]  client  The client
- * @param[in]  data    The data
- * @param[in]  len     The length
- * @param[in]  timeout Write data timeout in RTOS ticks
- *
- * @return
- *     - Number of data was sent
- *     - (-1) if any errors
- */
-int esp_websocket_client_send(esp_websocket_client_handle_t client, const char *data, int len, TickType_t timeout);
-
 /**
  * @brief      Write binary data to the WebSocket connection (data send with WS OPCODE=02, i.e. binary)
  *