rtl: fix lnd, lightning-loop connection errors

lnd and lightning-loop resolve `localhost` to an IPv4 address when
creating RPC sockets.

Since NixOS 23.05, RTL (nodejs) resolves `localhost` to an IPv6
address when connecting to lnd and lightning-loop, which leads to
connection errors.

To fix these and other potential errors, replace all instances
of `localhost` with `127.0.0.1`.

dev/dev-features.sh

@@ -275,9 +275,9 @@ c journalctl -u joinmarket-ob-watcher
 c journalctl -f -u joinmarket-ob-watcher
 
 # Check webinterface
-c curl localhost:62601
+c curl 127.0.0.1:62601
 nix run --inputs-from . nixpkgs#lynx -- --dump $ip:62601
-c curl -s localhost:62601 | grep -i "orders found"
+c curl -s 127.0.0.1:62601 | grep -i "orders found"
 
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 # rtl