Pin setuptools version for RHEL6 to 39.2
Pin setuptools version for RHEL6 to 39.2

Based on https://github.com/DBuildService/dockerfile-parse/commit/a1303f35edc462ef76413817d46537545238301d

Signed-off-by: Tim Waugh <fe049355006bf7fdd11c5e47ffe7a5032af30704@redhat.com>

DBuildService/osbs-client,DBuildService/osbs-client,projectatomic/osbs-client,projectatomic/osbs-client