Merge branch 'contrib/github_pr_15291' into 'master'

fix(esp_http_client): Fix invalid content length header (GitHub PR)

Closes IDFGH-14528

See merge request espressif/esp-idf!37036

Author: AdityaHPatwardhan

components/esp_http_client/esp_http_client.c

@@ -1590,6 +1590,8 @@ static int http_client_prepare_first_line(esp_http_client_handle_t client, int w
                                       client->connection_info.method != HTTP_METHOD_DELETE);
         if (write_len != 0 || length_required) {
             http_header_set_format(client->request->headers, "Content-Length", "%d", write_len);
+        } else {
+            http_header_delete(client->request->headers, "Content-Length");
         }
     } else {
         esp_http_client_set_header(client, "Transfer-Encoding", "chunked");