Phalanger Fix

While mcrypt_create_iv and MCRYPT_DEV_URANDOM are both available in Phalanger, when used it will generate a warning stating that the file (/dev/urandom) cannot be read from.

The !$buffer_valid check would catch this, however there would still be a warning generated every time a password was hashed.

In my opinion it is best to check if Phalanger is being used, and prevent this path from executing in the first place.