Ralph Mitchell reported a flaw when you used a proxy with auth, and you

Ralph Mitchell reported a flaw when you used a proxy with auth, and you
requested data from a host and then followed a redirect to another
host. libcurl then didn't use the proxy-auth properly in the second request,
due to the host-only check for original host name wrongly being extended to
the proxy auth as well. Added test case 233 to verify the flaw and that the
fix removed the problem.