Fix issue with Afraid.org hashes are being truncated.

The problem is that the return value hashes to http://freedns.afraid.org/api/?action=getdyndns&sha=[SHA1]
is > 36 characters (i.e. 44).  We should try to read to the end of the file.

Reported since 2010 in: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=781615