topgun: use busybox for http proxy... for now
topgun: use busybox for http proxy... for now

this wasn't working, and i don't really have time to investigate why -
it consistently failed with this error:

  + wget -Y on example.com
  --2020-10-23 13:54:02--  http://example.com/
  Resolving proxy.example.com (proxy.example.com)... failed: Name or service not known.
  wget: unable to resolve host address 'proxy.example.com'

not sure what would be so different between busybox wget and GNU wget.

Signed-off-by: Alex Suraci <925ba519bbf1a06224928b692ef88b93aee946af@gmail.com>

concourse/concourse,concourse/concourse,concourse/concourse,concourse/concourse,concourse/concourse