Bump src/collector for #66065824

See [story 66065824](https://www.pivotaltracker.com/story/show/66065824). This change is minor, makes collector backwards-compatible, and should be merged as soon as possible.

Bump cloudfoundry/collector:
  John Tuley:
     [#66065824] Listen for both "bad_requests" and "rejected_requests" from router ( Travis Success: https://travis-ci.org/cloudfoundry/collector/builds/19192300 )

Signed-off-by: John Tuley <jtuley@pivotallabs.com>