rpc: make addpeeraddress work with cjdns addresses

This allows us to add cjdns addresses to addrman for
testing and debug purposes (if -cjdnsreachable is true)

src/net.h

@@ -164,6 +164,7 @@ bool SeenLocal(const CService& addr);
 bool IsLocal(const CService& addr);
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer = nullptr);
 CService GetLocalAddress(const CNetAddr& addrPeer);
+CService MaybeFlipIPv6toCJDNS(const CService& service);
 
 
 extern bool fDiscover;

src/rpc/net.cpp

@@ -947,7 +947,8 @@ static RPCHelpMan addpeeraddress()
     bool success{false};
 
     if (LookupHost(addr_string, net_addr, false)) {
-        CAddress address{{net_addr, port}, ServiceFlags{NODE_NETWORK | NODE_WITNESS}};
+        CService service{net_addr, port};
+        CAddress address{MaybeFlipIPv6toCJDNS(service), ServiceFlags{NODE_NETWORK | NODE_WITNESS}};
         address.nTime = Now<NodeSeconds>();
         // The source address is set equal to the address. This is equivalent to the peer
         // announcing itself.