MFH: r486592

security/py-yubikey-manager: add missing (required) dependencies

• add missing depends to RUN_DEPENDS;
• add concurrent to USE_PYTHON, remove flavors;
• bump PORTREVISION.

PR: 233709
Submitted by: Daniel Shafer <daniel % shafer.cc>
Reviewed by: koobs
Approved by: araujo (mentor), miwi (ports-secteam)
Differential Revision: https://reviews.freebsd.org/D18419

Approved by: ports-secteam