fix: Send bcc-self messages to all own relays (#7656)

This fixes the bug when a new transport doesn't become primary on the 2nd device because INBOX from
the new transport isn't fully fetched. Now the `Transports` sync message is received from the old
transport, but as it has updated "From", it updates the primary transport correspondingly. NB: I/O
for the new primary transport isn't immediately started however, this needs a separate fix.

src/config.rs

@@ -967,7 +967,7 @@ impl Context {
         Ok(())
     }
 
-    /// Returns all primary and secondary self addresses.
+    /// Returns the primary self address followed by all secondary ones.
     pub(crate) async fn get_all_self_addrs(&self) -> Result<Vec<String>> {
         let primary_addrs = self.get_config(Config::ConfiguredAddr).await?.into_iter();
         let secondary_addrs = self.get_secondary_self_addrs().await?.into_iter();