Handle 'Connection: close' from proxies correctly

We should be looking for this as well as (or perhaps *instead* of) the
non-standard Proxy-Connection: header.

cf. http://homepage.ntlworld.com/jonathan.deboynepollard/FGA/web-proxy-connection-header.html

Reported-and-tested-by: Miloslav Švarc <miloslav.svarc@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

http.c

@@ -2062,7 +2062,8 @@ static int proxy_hdrs(struct openconnect_info *vpninfo, char *hdr, char *val)
 {
 	int i;
 
-	if (!strcasecmp(hdr, "Proxy-Connection")) {
+	if (!strcasecmp(hdr, "Proxy-Connection") ||
+	    !strcasecmp(hdr, "Connection")) {
 		if (!strcasecmp(val, "close"))
 			vpninfo->proxy_close_during_auth = 1;
 		return 0;