Manually merge r354962

This changes the fallback distfile download site to match what
the FreeBSD project is now doing.

Ticket: #5297
Part 2 of r354962: Point MASTER_SITES_LOCAL backup locations to static
servers with the actual data - in case of a geodns failure.

Approved by:	portmgr (bdrewery)

Manually merge r355790

Ticket: #5297