No longer send IPv6 information to CISCO clients that may not be able to handle it.

Now IPv6 information is only forwarded if the client is openconnect, or if
the client is unknown and has advertised full IPv6 support.

src/worker.h

@@ -81,6 +81,11 @@ enum {
 	S_AUTH_COMPLETE
 };
 
+enum {
+	AGENT_UNKNOWN,
+	AGENT_OPENCONNECT
+};
+
 typedef struct dtls_ciphersuite_st {
 	const char* oc_name;
 	const char* gnutls_name; /* the gnutls priority string to set */
@@ -99,6 +104,7 @@ struct http_req_st {
 
 	char hostname[MAX_HOSTNAME_SIZE];
 	char user_agent[MAX_AGENT_NAME];
+	unsigned user_agent_type;;
 
 	unsigned int next_header;
 	unsigned char cookie[COOKIE_SIZE];