Update exp_for_php.py

Author: tarunkant

hitcon-ctf-2018/one-line-php-challenge/exp_for_php.py

@@ -24,6 +24,7 @@
     xx = b64encode(b64encode(payload + junk))
     xxx = b64encode(b64encode(b64encode(payload + junk)))
     if '=' not in x and '=' not in xx and '=' not in xxx:
+        payload = xxx
         print payload
         break