ESP8266 cannot create TCP connections to this particular server
Not a cookie cutter answer, I did a quick test and my ESP8266 does connect to you nginx. Of course you do not accept the params from my fridge, but this is what I see in the log.

7007 :
7010 :

For online documentation and support please refer to
7012 : nginx.org.

7015 : Commercial support is available at
7018 : nginx.com.

7020 :
7022 :

Thank you for using nginx.

7024 :
7026 :
7028 : HTTP : closing connection


You should be able to see that on your side as well.

I am using letscontrolit/ESPEASY  https://github.com/letscontrolit/ESPEasy 

And their code to connect looks like

  // Use WiFiClient class to create TCP connections
  WiFiClient client;
  if (!ControllerSettings.connectToHost(client))
  {
    connectionFailures++;
    addLog(LOG_LEVEL_ERROR, F("HTTP : connection failed"));
    return false;
}

  boolean connectToHost(WiFiClient &amp;client) {
    if (!checkHostReachable(true)) {
      return false; // Host not reachable
    }
    byte retry = 2;
    bool connected = false;
    while (retry &gt; 0 &amp;&amp; !connected) {
      --retry;
      connected = client.connect(getIP(), Port);
      if (connected) return true;
      if (!checkHostReachable(false))
        return false;
    }
    return false;
}


I am using generic HTTP for my controller which here: https://github.com/letscontrolit/ESPEasy/blob/503fd3555e010b08b48fb2dc18290ef120005308/src/_C008.ino

You could try the connect to function to see if that works for you.