security/dehydrated: Update to 0.6.5

While I'm here, pet portlint:

WARN: Makefile: extra item placed in the USES/USE_x section, for example, "NO_BUILD".

Changelog:

https://github.com/lukas2511/dehydrated/blob/v0.6.5/CHANGELOG

PR: 238918
Submitted by: Sascha Holzleiter <sascha root-login org> (maintainer)
MFH: 2019Q2 (blanket: bugfix release)