apply test naming suggestion

Author: Simon-Laux

src/download.rs

@@ -539,8 +539,7 @@ mod tests {
     /// Tests that pre message has autocrypt gossip headers and self avatar
     /// and full message doesn't have these headers
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-    async fn test_pre_message_contains_selfavatar_and_gossip_and_full_message_does_not()
-    -> Result<()> {
+    async fn test_selfavatar_and_autocrypt_gossip_goto_pre_message() -> Result<()> {
         let mut tcm = TestContextManager::new();
         let alice = tcm.alice().await;
         let bob = tcm.bob().await;