prefer public ipv6 instead rfc4941 (closes #1251)

Wokrs only on linux-based systems. Not tested on other *nix systems, and
not works on windows.

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd/util.h

@@ -177,13 +177,13 @@ namespace util
 
 			SaveStateHelper (T& orig): m_Original (orig), m_Copy (orig) {};
 			~SaveStateHelper () { m_Original = m_Copy; };
-			
+
 		private:
 
 			T& m_Original;
 			T m_Copy;
-	};	
-	
+	};
+
 	namespace net
 	{
 		int GetMTU (const boost::asio::ip::address& localAddress);