internal: fix link in error page or matching versions
internal: fix link in error page or matching versions

Change-Id: Ia14436f3e99890ce9830ab1acb1e5e5d884142cb
Reviewed-on: https://team-review.git.corp.google.com/c/golang/discovery/+/502199
Reviewed-by: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>

golang/pkgsite,golang/pkgsite,golang/pkgsite,golang/pkgsite