fix up local/external address handling

src/NetworkAddresses.hh

@@ -12,6 +12,7 @@
 uint32_t resolve_address(const char* address);
 std::map<std::string, uint32_t> get_local_addresses();
 uint32_t get_connected_address(int fd);
+bool is_loopback_address(uint32_t addr);
 bool is_local_address(uint32_t daddr);
 bool is_local_address(const sockaddr_storage& daddr);