www/palemoon: Update to 27.6.2

• Add SNDIO option
• Include bug fixes that improve A/V sync with SNDIO=on [1]
• Allow armv6 build

Changes: http://www.palemoon.org/releasenotes.shtml
PR: 223934, 215867 [1]
Submitted by: lichray@gmail.com (maintainer)
Security: 6056bf68-f570-4e70-b740-b9f606971283