Fix Timeout Bug in WebServer

[vicatcu]

Take a look at this line of code

      if (_currentClient.available()) {
        if (_parseRequest(_currentClient)) {
          _currentClient.setTimeout(HTTP_MAX_SEND_WAIT); // <-- THIS LINE
          _contentLength = CONTENT_LENGTH_NOT_SET;
          _handleRequest();
          ...

Observe that HTTP_MAX_SEND_WAIT expands to 5000 (here)

Review the definition of setTimeout in WiFiClient class which subsequently passes the value to the Client class as follows

WiFiClient::setTimeout(uint32_t seconds) { // <-- NOT MILLISECONDS
    Client::setTimeout(seconds * 1000);    // <-- NOTICE x1000
    struct timeval tv;
    tv.tv_sec = seconds;
    ...

Solution is to divide it by 1000 in the call to setTimeout. Alternative solution would be to re-define the HTTP_MAX_SEND_WAIT to be defined in seconds instead of milliseconds, but that would be different from the surrounding defines, which is why I opted for the proposed implementation. The compiler should shake out the maths anyway.