security/py-{acme,certbot}: update to 0.19.0

[cpm]

Summary

Common:

- Update PORTVERSION and distinfo checksum (0.19.0)

Changelog: https://github.com/certbot/certbot/blob/master/CHANGELOG.md#0190---2017-10-04

Reviewed_by: koobs (maintainer)
Approved by: koobs (maintainer, py-certbot)
Differential_Revision: D12482

Test Plan

portlint: OK (looks fine.)
testport: OK (poudriere: {12,11,10}{i386,amd64}
maketest: OK

[cpm]

Update to 0.19.0