bump atc
bump atc

Submodule src/github.com/concourse/atc adeb805..f47a4ab:
  > nuke 'loading...' text

cjcjameson/concourse,concourse/concourse,concourse/concourse,cjcjameson/concourse,concourse/concourse,concourse/concourse,concourse/concourse,cjcjameson/concourse