You are missing a CR/LF in your code. You must send a blank line to let the server know you are finished sending the request header. Try this instead.
client.println("GET /test.php HTTP/1.0\r\n");
You are missing a CR/LF in your code. You must send a blank line to let the server know you are finished sending the request header. Try this instead.
client.println("GET /test.php HTTP/1.0\r\n");