Red Hat Satellite Proxy always downloads yum metadata, even if it has not changed

First ensure that the Satellite 5.7 instance that Proxy is connected to has applied RHBA-2015:0887. Then, on the Proxy:

1) As root edit /etc/squid/squid.conf and change the line

refresh_pattern /XMLRPC/GET-REQ/.*/repodata/.*\.xml.*$ 0 1% 525960

to be

refresh_pattern /XMLRPC/GET-...