apply cargo warning suggested fixes

Signed-off-by: William Casarin <jb55@jb55.com>

enostr/src/event.rs

@@ -1,5 +1,5 @@
 use crate::{Error, Pubkey};
-use log::debug;
+
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use std::hash::{Hash, Hasher};