Comment 12 for bug 1551351

Looking at the changelog history of bind9, the change to 9.10 looks to be older (around December last year) but then only a recent upload to isc-dhcp mentions "Link with the non-export bind9 libraries". Which I think we can assume is what causes the problem. That went to the archive around noon on Feb-28th which would match my time-line of noticing it.