Increase max-age for Strict-Transport-Security header

Currently the header is:
Strict-Transport-Security: max-age=10886400; includeSubDomains; preload

But to be able to add it to the preload list, in addition to having specified preload it also has to have a max-age of minimum 31536000.

The preload list submission page recommends setting max-age to 2 years, 63072000

_Error: Max-age too low
The max-age must be at least 31536000 seconds (≈ 1 year), but the header currently only has max-age=10886400._