osx fix

AddressBook.cpp

@@ -543,7 +543,9 @@ namespace client
 		auto dest = i2p::client::context.GetSharedLocalDestination ();
 		if (dest)
 		{
-			auto datagram = dest->CreateDatagramDestination ();
+      
+			auto datagram = dest->GetDatagramDestination ();
+      if(datagram == nullptr) datagram = dest->CreateDatagramDestination();
 			datagram->SetReceiver (std::bind (&AddressBook::HandleLookupResponse, this, 
 				std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, std::placeholders::_4, std::placeholders::_5), 
 				ADDRESS_RESPONSE_DATAGRAM_PORT);