Single supported nip creates invalid json

[davotoula]

According to nip-11 spec, the supported_nips should always be a list.

When a relay only supports a single nip, then the single nip id is returned as an int instead of a list-of-one.

This causes json errors (in amethyst).

[davotoula]

Spec: https://github.com/nostr-protocol/nips/blob/master/11.md

"supported_nips": <a list of NIP numbers supported by the relay>,

Json returned by https://purplepag.es/

,"supported_nips":1,

[davotoula]

Patch to always return list:

diff --git a/src/apps/relay/RelayWebsocket.cpp b/src/apps/relay/RelayWebsocket.cpp
index b87de56..86657f4 100644
--- a/src/apps/relay/RelayWebsocket.cpp
+++ b/src/apps/relay/RelayWebsocket.cpp
@@ -53,7 +53,14 @@ void RelayServer::runWebsocket(ThreadPool<MsgWebsocket>::Thread &thr) {
         if (cfg().relay__info__nips.size() == 0) return output;
 
         try {
-            output = tao::json::from_string(cfg().relay__info__nips);
+			auto v = tao::json::from_string(cfg().relay__info__nips);
+		
+			if (v.is_array()) {
+				output = std::move(v);
+			} else {
+				// Wrap any non-array in an array
+				output = tao::json::value::array({ std::move(v) });
+			}
         } catch (std::exception &e) {
             LE << "Unable to parse config param relay.info.nips: " << e.what();
         }