Adjust canonical links to match the current version redirects

The issue was discovered in `https://github.com/boostorg/website-v2/issues/2116`. On `mailing_lists.htm` the canonical link and the current version link varied. The same result likely occurs on many pages.

I believe the "current version" information is newer, more correct, and more advanced. The canonical link lags behind.
Canonical should be adjusted to match the current version info. They would both be identical.