refactor: don't return Err(Error::BufferedFutureMessage) from `hand…

…le_future_message()`

This was meaningless because in the one and only caller this error would always be propagated.
So we can just keep it in that context and raise it from there directly.
No need for an extra round trip.

(cherry picked and adjusted from commit 5d7af36)

crypto/src/mls/conversation/buffer_messages.rs

@@ -8,7 +8,7 @@ use crate::{
     group_store::GroupStoreValue,
     prelude::{
         decrypt::MlsBufferedConversationDecryptMessage, Client, ConversationId, CoreCryptoCallbacks, CryptoError,
-        CryptoResult, MlsConversation, MlsConversationDecryptMessage, MlsError,
+        CryptoResult, MlsConversation, MlsError,
     },
 };
 use core_crypto_keystore::{
@@ -25,15 +25,15 @@ impl CentralContext {
         &self,
         id: &ConversationId,
         message: impl AsRef<[u8]>,
-    ) -> CryptoResult<MlsConversationDecryptMessage> {
+    ) -> CryptoResult<()> {
         let keystore = self.keystore().await?;
 
         let pending_msg = MlsPendingMessage {
             foreign_id: id.clone(),
             message: message.as_ref().to_vec(),
         };
         keystore.save::<MlsPendingMessage>(pending_msg).await?;
-        Err(CryptoError::BufferedFutureMessage)
+        Ok(())
     }
 
     pub(crate) async fn restore_pending_messages(