Based on further discussion on curl-library, I reverted yesterday's SOCKS5

code to instead introduce support for a new proxy type called
CURLPROXY_SOCKS5_HOSTNAME that is used to send the host name to the proxy
instead of IP address and there's thus no longer any need for a new
curl_easy_setopt() option.

The default SOCKS5 proxy is again back to sending the IP address to the
proxy.  The new curl command line option for enabling sending host name to a
SOCKS5 proxy is now --socks5-hostname.

lib/socks.c

@@ -390,7 +390,7 @@ CURLcode Curl_SOCKS5(const char *proxy_name,
   curl_socket_t sock = conn->sock[sockindex];
   struct SessionHandle *data = conn->data;
   long timeout;
-  bool socks5_resolve_local = data->set.socks5_resolve_local;
+  bool socks5_resolve_local = data->set.proxytype == CURLPROXY_SOCKS5;
   const size_t hostname_len = strlen(hostname);
   int packetsize = 0;