Update dir-spec descriptor cosmetic difference criteria (12 hours -> 2 hours)
In section 3.2 of the dir-spec document it says:
If the authority _does_ have a descriptor with the same public key, the
newly uploaded descriptor is remembered if its publication time is more
recent than the most recent old descriptor for that router, and either:
- There are non-cosmetic differences between the old descriptor and the
new one.
- Enough time has passed between the descriptors' publication times.
(Currently, 12 hours.)
This value of 12 hours was change in commit cc351578 to 2 hours.
In addition, a comment in the tor code still says 12 hours.
This ticket covers two changes:
- update the dir-spec to say 2 hours
- update a comment in the tor code
Will attach two PRs shortly.