[release-branch.go1.12] doc: fix bad lib/time link in 1.12 release notes
There's a "lib/time" sub-section in the Go 1.12 relase notes that
points to a non-existent golang.org/pkg/lib/time page.
The note is about a change in the tz database in the src/lib/time
directory, but the section's title (and the link) should probably just
refer to the time package.
Change-Id: Ibf9dacd710e72886f14ad0b7415fea1e8d25b83a
Reviewed-on: https://go-review.googlesource.com/c/164977
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
(cherry picked from commit
0dc62565401eba11bf9aec127c6c9f5aa4ecf1c9)
Reviewed-on: https://go-review.googlesource.com/c/164964
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>