feat!: remove a relay immediately instead of unpublishing it

Removing a relay now takes effect immediately:

- the profile stops fetching and advertising it,

- secondary devices immediately apply the removal through the transport sync,

Upgrading removes unpublished relays and triggers keyupdates.

BREAKING CHANGE: set_transport_unpublished() is removed: UIs call delete_transport() when the user removes a relay.

BREAKING CHANGE: list_transports_ex() and the TransportListEntry type are removed: use list_transports().

BREAKING CHANGE: delete_transport() no longer refuses to remove the primary transport: it refuses only to remove the last one and re-elects the sending transport as needed.

BREAKING CHANGE: TransportsModified is now also emitted on the device modifying the transports, not only on devices applying the synced change.

Deprecated: DC_STR_PHASING_OUT

src/smtp.rs

@@ -733,9 +733,12 @@ pub(crate) async fn add_self_recipients(
     // Avoid sending unencrypted messages to all transports, chatmail relays won't accept
     // them. Normally the user should have a non-chatmail primary transport to send unencrypted
     // messages.
+    let from = context.get_primary_self_addr().await?;
     if encrypted {
-        for addr in context.get_published_secondary_self_addrs().await? {
-            recipients.push(addr);
+        for addr in context.get_self_addrs().await? {
+            if addr != from {
+                recipients.push(addr);
+            }
         }
     }
     // `from` must be the last addr
@@ -744,7 +747,6 @@ pub(crate) async fn add_self_recipients(
     // This helps with marking messages as delivered
     // if the server is slow and we never get an `OK` response
     // before the connection times out.
-    let from = context.get_primary_self_addr().await?;
     recipients.push(from);
 
     Ok(())