Use correct custom header without double/single quote http-proxy-option CUSTOM-HEADER "Host: example.com"
must be http-proxy-option CUSTOM-HEADER Host example.com
. Also avoid "https://" , that protocol are only available for ssl-bumped proxy software builds, kagaya po nitong script na to (squid 3.1 stable).
Sa Ubuntu naman po, use OHPServer+OpenVPN method.. since i-aacept po nun lahat ng request headers kahit improper or broken headers pa po ang gamit.
Sa debian since 3.5 wala na pong ssl feature, di na po gagana yung "https://" and sensitive na po sya sa buffer sizes kaya di na po sya gagana sa double/single quoting style na custom headers