Error(-11): read Timeout for long JSON in POST requests

### Basic Infos

- [ X] This issue complies with the [issue POLICY doc](https://github.com/esp8266/Arduino/blob/master/POLICY.md).
- [X ] I have read the documentation at [readthedocs](https://arduino-esp8266.readthedocs.io/en/latest) and the issue is not addressed there.
- [ X] I have tested that the issue is present in current master branch (aka latest git).
- [ X] I have searched the issue tracker for a similar issue.
- [ ] If there is a stack dump, I have decoded it.
- [X ] I have filled out all fields below.

#### Platform

- Hardware: [ESP-12|ESP-01|ESP-07|ESP8285 device|other]
- Core Version: [latest git hash or date]
- Development Env: [Arduino IDE|Platformio|Make|other]
- Operating System: [Windows|Ubuntu|MacOS]

### Settings in IDE

- Module: [Generic ESP8266 Module|Wemos D1 mini r2|Nodemcu|other]
- Flash Mode: [qio|dio|other]
- Flash Size: [4MB/1MB]
- lwip Variant: [v1.4|v2 Lower Memory|Higher Bandwidth]
- Reset Method: [ck|nodemcu]
- Flash Frequency: [40Mhz]
- CPU Frequency: [80Mhz|160MHz]
- Upload Using: [OTA|SERIAL]
- Upload Speed: [115200|other] (serial upload only)

### Problem Description

Hi, I send an HTTP POST request with a JSON to my server and it works, but when I tried to send a longer JSON POST with a size 2940 of capacity or as with 1666 characters, or more, the response code is (-11) read timeout. I tried to change the CPU frequency, other features of the module, and the set time out, but didn't work fine. I send the same HTTP POST request in POSTMAN and this works correctly.
Thanks

### [MCVE](https://stackoverflow.com/help/mcve) Sketch

```cpp

#include
#include
#include
#include

const char* wifiName = "******";
const char* wifiPass = "******";

//Web Server address to read/write from
const char *host = "http://development.plantit.io/device/getState/?device_id=1";

void setup() {

Serial.begin(115200);
delay(10);
Serial.println("Comienza");

Serial.print("Connecting to ");
Serial.println(wifiName);

WiFi.begin(wifiName, wifiPass);

while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}

Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP()); //You can get IP address assigned to ESP
}

void loop() {

HTTPClient http;
http.setTimeout(60000); //Se configura el tiempo de espera para realizar la conexión
String SdJson = "[{\"sensor\":{\"S1\":{\"T\":99,\"H\":60.73},\"S2\":{\"T\":22.22,\"H\":86.22},\"S3\":{\"T\":19.45,\"H\":71.98},\"S4\":{\"T\":25.67,\"H\":49.67}},\"SLAL\":{\"SLAL1\":0,\"SLAL2\":0,\"SLAL3\":0,\"SLAL4\":0},\"device\":{\"MAC\":\"50:02:91:4D:F6:ED\",\"type\":\"prueba\",\"function\":\"prueba\",\"n_devices\":4,\"id\":\"XXX\",\"GateWayIP\":\"192.168.4.1\"},\"SLAG\":{\"SLAG1\":0,\"SLAG2\":0,\"SLAG3\":0,\"SLAG4\":0},\"times\":{\"time1\":\"12:00\"}},{\"sensor\":{\"S1\":{\"T\":99,\"H\":60.73},\"S2\":{\"T\":22.22,\"H\":86.22},\"S3\":{\"T\":19.45,\"H\":71.98},\"S4\":{\"T\":25.67,\"H\":49.67}},\"SLAL\":{\"SLAL1\":0,\"SLAL2\":0,\"SLAL3\":0,\"SLAL4\":0},\"device\":{\"MAC\":\"50:02:91:4D:F6:ED\",\"type\":\"prueba\",\"function\":\"prueba\",\"n_devices\":4,\"id\":\"XXX\",\"GateWayIP\":\"192.168.4.1\"},\"SLAG\":{\"SLAG1\":0,\"SLAG2\":0,\"SLAG3\":0,\"SLAG4\":0},\"times\":{\"time1\":\"12:00\"}},{\"sensor\":{\"S1\":{\"T\":99,\"H\":60.73},\"S2\":{\"T\":22.22,\"H\":86.22},\"S3\":{\"T\":19.45,\"H\":71.98},\"S4\":{\"T\":25.67,\"H\":49.67}},\"SLAL\":{\"SLAL1\":0,\"SLAL2\":0,\"SLAL3\":0,\"SLAL4\":0},\"device\":{\"MAC\":\"50:02:91:4D:F6:ED\",\"type\":\"prueba\",\"function\":\"prueba\",\"n_devices\":4,\"id\":\"XXX\",\"GateWayIP\":\"192.168.4.1\"},\"SLAG\":{\"SLAG1\":0,\"SLAG2\":0,\"SLAG3\":0,\"SLAG4\":0},\"times\":{\"time1\":\"12:00\"}},{\"sensor\":{\"S1\":{\"T\":99,\"H\":60.73},\"S2\":{\"T\":22.22,\"H\":86.22},\"S3\":{\"T\":19.45,\"H\":71.98},\"S4\":{\"T\":25.67,\"H\":49.67}},\"SLAL\":{\"SLAL1\":0,\"SLAL2\":0,\"SLAL3\":0,\"SLAL4\":0},\"device\":{\"MAC\":\"50:02:91:4D:F6:ED\",\"type\":\"prueba\",\"function\":\"prueba\",\"n_devices\":4,\"id\":\"XXX\",\"GateWayIP\":\"192.168.4.1\"},\"SLAG\":{\"SLAG1\":0,\"SLAG2\":0,\"SLAG3\":0,\"SLAG4\":0},\"times\":{\"time1\":\"12:00\"}}]";
// "[{\"sensor\":{\"S1\":{\"T\":99,\"H\":60.73},\"S2\":{\"T\":22.22,\"H\":86.22},\"S3\":{\"T\":19.45,\"H\":71.98},\"S4\":{\"T\":25.67,\"H\":49.67}},\"SLAL\":{\"SLAL1\":0,\"SLAL2\":0,\"SLAL3\":0,\"SLAL4\":0},\"device\":{\"MAC\":\"50:02:91:4D:F6:ED\",\"type\":\"prueba\",\"function\":\"prueba\",\"n_devices\":4,\"id\":\"XXX\",\"GateWayIP\":\"192.168.4.1\"},\"SLAG\":{\"SLAG1\":0,\"SLAG2\":0,\"SLAG3\":0,\"SLAG4\":0},\"times\":{\"time1\":\"12:00\"}},{\"sensor\":{\"S1\":{\"T\":99,\"H\":60.73},\"S2\":{\"T\":22.22,\"H\":86.22},\"S3\":{\"T\":19.45,\"H\":71.98},\"S4\":{\"T\":25.67,\"H\":49.67}},\"SLAL\":{\"SLAL1\":0,\"SLAL2\":0,\"SLAL3\":0,\"SLAL4\":0},\"device\":{\"MAC\":\"50:02:91:4D:F6:ED\",\"type\":\"prueba\",\"function\":\"prueba\",\"n_devices\":4,\"id\":\"XXX\",\"GateWayIP\":\"192.168.4.1\"},\"SLAG\":{\"SLAG1\":1,\"SLAG2\":1,\"SLAG3\":0,\"SLAG4\":1},\"times\":{\"time1\":\"12:00\"}}]";
int lenoutput = SdJson.length();
const size_t sdcapacity = lenoutput * 3; //Capacidad del JSON a almacenar en la conexión del Cliente
DynamicJsonDocument sdroot(sdcapacity);//Declaración JSON
auto error = deserializeJson(sdroot, SdJson); //Deserialización del Json, para añadirle el SLA Global y reenviar al Servidor global
if (error) { //Condición de error de deserialización
Serial.println(F("deserializeJson() failed with code"));
Serial.println(error.c_str()); //Mensaje de error en específico
return; //Se rompe el ciclo
}
JsonObject obje = sdroot.as(); //Declaración jsonobject con el mensaje proveniente del client
String sdoutput; //Declaración String JSON a enviar al servidor con toda la información del slave
serializeJson(sdroot, sdoutput); //Serialización del JSONObject con el string JSON a enviar
// Send request
http.begin(host);
Serial.println("Post!");

// Serial.println(SdJson); //Se Imprime el JSON para su comprobación
int httpCode = http.POST(sdoutput); // POST request con el JSON del cliente al servidor global

if (httpCode > 0) { //Condición de conexión exitosa
Serial.printf("[HTTP] GET... code: %d\n", httpCode); //Código obtenido de la respuesta exitosa
}
else { //Condición de fallo en conexión al servidor global
Serial.printf("[HTTP] POST... failed, error: %s\n", http.errorToString(httpCode).c_str()); //Impresión de error en conexión Global
}

// Disconnect
http.end();
}
```

### Debug Messages

WiFi connected
IP address:
192.168.0.3
[HTTP-Client][begin] url: http://development.plantit.io/device/getState/?device_id=1
[HTTP-Client][begin] host: development.plantit.io port: 80 url: /device/getState/?device_id=1
Post!
[HTTP-Client][sendRequest] type: 'POST' redirCount: 0
[HTTP-Client] connected to development.plantit.io:80
[HTTP-Client] sending request header

POST /device/getState/?device_id=1 HTTP/1.1
Host: development.plantit.io
User-Agent: ESP8266HTTPClient
Connection: keep-alive
Accept-Encoding: identity;q=1,chunked;q=0.1,*;q=0
Content-Length: 1465

[HTTP-Client][returnError] error(-11): read Timeout
[HTTP-Client][returnError] tcp stop
[HTTP] POST... failed, error: read Timeout
[HTTP-Client][end] tcp is closed