Fix endpoint URL

docs/event-dispatcher.md

@@ -6,7 +6,7 @@ This is enabled by adding an entry to the node's `config.toml` file:
 ```toml
 ...
 [[events_observer]]
-endpoint = "http://listener:3700"
+endpoint = "listener:3700"
 events_keys = [
   "*"
 ]

testnet/stacks-node/src/event_dispatcher.rs

@@ -46,7 +46,7 @@ impl EventObserver {
         };
 
         let url = {
-            let url = format!("{}{}", &self.endpoint, path);
+            let url = format!("http://{}/{}", &self.endpoint, path);
             Url::parse(&url).expect(&format!("Unable to parse {} as a URL", url))
         };