simplify sorting with sort_by_key

Author: antonilol

integration_test/src/main.rs

@@ -1433,15 +1433,7 @@ fn test_get_zmq_notifications(cl: &Client) {
 
     // it doesn't matter in which order Bitcoin Core returns the result,
     // but checking it is easier if it has a known order
-    zmq_info.sort_by(|a, b| {
-        if a.address < b.address {
-            Ordering::Less
-        } else if a.address == b.address {
-            Ordering::Equal
-        } else {
-            Ordering::Greater
-        }
-    });
+    zmq_info.sort_by_key(|result| &result.address);
 
     assert!(
         zmq_info