Fix accidental newline in OnionMessenger docs

Author: valentinewallace

lightning/src/onion_message/messenger.rs

@@ -61,8 +61,7 @@ use prelude::*;
 /// # let node_secret = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 /// # let secp_ctx = Secp256k1::new();
 /// # let hop_node_id1 = PublicKey::from_secret_key(&secp_ctx, &node_secret);
-/// # let (hop_node_id2, hop_node_id3, hop_node_id4) = (hop_node_id1, hop_node_id1,
-/// hop_node_id1);
+/// # let (hop_node_id2, hop_node_id3, hop_node_id4) = (hop_node_id1, hop_node_id1, hop_node_id1);
 /// # let destination_node_id = hop_node_id1;
 /// # let your_custom_message_handler = IgnoringMessageHandler {};
 /// // Create the onion messenger. This must use the same `keys_manager` as is passed to your