hsts: increase age to 6 months

[grahamc]

6mo is long enough we are a step closer to being able to "preload" hsts support. After this, we'd need to ensure all subdomains supported HSTS. Do you have a list?

• releases.nixos.org
• planet.nixos.org
• hydra.nixos.org
• test.nixos.org
• test2.nixos.org
• ipv6.nixos.org

anything I missed?

[edolstra]

Here are all subdomains:

barbrady.nixos.org
cache.nixos.org
conf.nixos.org
hydra-test.nixos.org
hydra.nixos.org
losser.nixos.org
lucifer.nixos.org
monitor.nixos.org
mturk.nixos.org
planet.nixos.org
releases-tmp.nixos.org
releases.nixos.org
stan.nixos.org
status.nixos.org
svn.nixos.org
tarballs.nixos.org
ts.nixos.org
weekly.nixos.org

Many of these are obsolete.