MFH: r509978 r510809
www/firefox: update to 69.0
Changes: https://www.mozilla.org/firefox/69.0/releasenotes/
PR: 239155
Security: 05463e0a-abd3-4fa4-bd5f-cd5ed132d4c6
Approved by: ports-secteam (joneum)
Differential Revision: https://reviews.freebsd.org/D20932