feat(NIP-22): advertise support for event created_at limits

The `reject_future_limits` option can now be disabled, and is by
default.

NIP-11 advertises support for created_at limits.

The message for future-dated events has been modified, to be closer to
the recommended example in the NIP.

src/config.rs

@@ -219,7 +219,7 @@ impl Default for Settings {
                 whitelist_addresses: None, // whitelisted addresses (never delete)
             },
             options: Options {
-                reject_future_seconds: Some(30 * 60), // Reject events 30min in the future or greater
+                reject_future_seconds: None, // Reject events in the future if defined
             },
         }
     }

src/info.rs

@@ -35,7 +35,7 @@ impl From<config::Info> for RelayInfo {
             description: i.description,
             pubkey: i.pubkey,
             contact: i.contact,
-            supported_nips: Some(vec![1, 2, 11, 15, 16]),
+            supported_nips: Some(vec![1, 2, 11, 15, 16, 22]),
             software: Some("https://git.sr.ht/~gheartsfield/nostr-rs-relay".to_owned()),
             version: CARGO_PKG_VERSION.map(|x| x.to_owned()),
         }

src/server.rs

@@ -529,8 +529,9 @@ async fn nostr_server(
                                     client_published_event_count += 1;
                 } else {
                     info!("client {:?} sent a far future-dated event", cid);
-                    ws_stream.send(make_notice_message("event was too far in the future")).await.ok();
-
+                    if let Some(fut_sec) = settings.options.reject_future_seconds {
+                    ws_stream.send(make_notice_message(&format!("The event created_at field is out of the acceptable range (+{}sec) for this relay and was not stored.",fut_sec))).await.ok();
+                    }
                 }
                             },
                             Err(_) => {