Revert "Revert "Merge pull request #317 from prometheus/fix/miekg-dns-for-srv""

This reverts commit 88099328d1a899b649141ba8c77933fac91eabbb.

Change-Id: I7bf74de5fda458e2e6f9eea2eacd0e256f95bdee
Merge "Revert "Revert "Merge pull request #317 from prometheus/fix/miekg-dns-for-srv"""