CHANGELOG: add clarification
CHANGELOG: add clarification

kenichiii/phpseclib,splitice/phpseclib,creatuity/phpseclib,creatuity/phpseclib,melya/phpseclib,danog/phpseclib,danog/phpseclib,terrafrost/phpseclib,metaclassing/phpseclib,thaigialai1987/phpseclib,phpseclib/phpseclib,metaclassing/phpseclib,melya/phpseclib,paragonie-scott/phpseclib,thaigialai1987/phpseclib,splitice/phpseclib,paragonie-scott/phpseclib,kenichiii/phpseclib