Update readme

Author: Mustafa ÖNCEL

README.md

@@ -41,7 +41,7 @@ public class Main {
 
 		if(o instanceof ResponseType) {
 
-			throw new IllegalArgumentException("An error occured when validating your account. The web server response is: " + ((ResponseType) o).toString());
+			System.out.println("An error occured when validating your account. The web server response is: " + ((ResponseType) o).toString());
 
 		} else if(o instanceof User) {