MFH: r478268 r478506
www/firefox: update to 62.0
Changes: https://www.mozilla.org/firefox/62.0/releasenotes/
PR: 229168
Security: c96d416a-eae7-4d5d-bc84-40deca9329fb
Approved by: ports-secteam (miwi)
Differential Revision: https://reviews.freebsd.org/D15913