connections to remote sites time out, waiting for DNS resolution.
The logic to detect various flavours of SOCKS proxy and ask the
libcurl layer to use appropriate one understands the proxy string
that begin with socks5, socks4a, etc., but does not know socks5h,
and we end up using CURLPROXY_SOCKS5. The correct one to use is
CURLPROXY_SOCKS5_HOSTNAME.