allow unused for MAX_FETCH_MSG_SIZE

Author: Simon-Laux

src/download.rs

@@ -26,6 +26,7 @@ pub(crate) const PRE_MESSAGE_ATTACHMENT_SIZE_THRESHOLD: u64 = 140_000;
 /// Max message size to be fetched in the background.
 /// This limit defines what messages are fully fetched in the background.
 /// This is for all messages that don't have the full message header.
+#[allow(unused)]
 pub(crate) const MAX_FETCH_MSG_SIZE: usize = 1_000_000;
 
 /// Max size for pre messages. A warning is emitted when this is exceeded.