New patch to fix FTBFS with golang-github-docker-distribution-dev >= 2.7.1 (Closes: #944346)

 Unfortunately there is another problem:

~~~~
src/github.com/theupdateframework/notary/server/server.go:127:9: undefined: prometheus.InstrumentHandlerWithOpts
src/github.com/theupdateframework/notary/server/server.go:235:44: undefined: prometheus.Handler
~~~~
1 job for master in 7 minutes and 35 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #406535
test_the_archive

00:07:35