Revert handling of anchor text to 8.x-2.x
SpamSpan 3.x preserves mail-addresses in anchor text. This creates issues when the mail-addresses contains the strings 'at' or 'dot' or when the domain-part of the address contains dots or dashes. It also degrades the obfuscation-level of the filter, as the pattern at for @ and dot for . is known to many spambots.