Arduino retrieving PHP echo using ESP8266
It looks like you post request may be missing a CRLF at the end (it needs two) and some spaces.

I think you need this:

 String postRequest = "GET " + location + "\r\nHTTP 1.0\r\n\r\n";


My suggestion would be to get a REST client (like the one you can get for Chrome as an App) and send the message to your server through that and see what the difference is.