Investigating how squid behaved with jesred I found a workaround while we don't find a proper solution, this is really ugly but it works for me in the meanwhile:
regex ^http://matchedurl url=http://replacementurl This is working for current jessie 3.4.8-6+deb8u1 but may not work on any other version, I didn't even look at squid's code to see how this works, I just guessed this would work with a few tests, so it may not work for anybody else. Regards. -- Manty/BestiaTester -> http://manty.net