Try to distinguish varnish headers from intermediate proxies

Just a workaround to avoid the scenario of using this plugin where an intermediate proxy also sends an "X-Cache" header

Assumes X-Varnish header is set and therefore relies on the two integers. The second which implies a cache hit

See https://www.varnish-cache.org/docs/2.1/faq/http.html

Not bothered if this doesn't suit you. Just thought I'd share this