Fix formatting output of admin debug get-retained-pdu

src/admin/debug/commands.rs

@@ -1034,7 +1034,7 @@ pub(super) async fn get_retained_pdu(&self, event_id: OwnedEventId) -> Result {
 
 	let text = serde_json::to_string_pretty(&pdu)?;
 
-	self.write_str(&format!("Original PDU:\n```json\n{text}```"))
+	self.write_str(&format!("Original PDU:\n```json\n{text}\n```"))
 		.await?;
 
 	Ok(())