www/chromium: update to 80.0.3987.132
This addresses some security issues, including at least one Google admits was
being exploited in the wild. For more, see:
https://chromereleases.googleblog.com/2020/02/stable-channel-update-for-desktop_24.html
PR: 244625
Approved by: jrm, rene
Security: CVE-2020-6407, CVE-2020-6418 (in the wild), CVE-2020-6420
Differential Revision: https://reviews.freebsd.org/D23984