Zend Framework Bug-Fix for PHP 5.6

Reference: https://tracker.moodle.org/browse/MDL-49526

This patch is for the Zend Framework being out of date on Moodle, some plugins that use the Zend Framework on PHP 5.6 servers will experience an issue with the iconv_get and iconv_set parameters caled by the legacy framework.

The patch changes are in: moodle/lib/zend/Zend/Validate/Hostname.php

Comment out lines 513 & 514
add (below 514):
$origenc = mb_internal_encoding();
mb_internal_encoding('UTF-8');

Comment out line 611.
add (below 611): mb_internal_encoding($origenc);

This replicates the changed code with the new call mb_internal_encoding()