1.152.1 and 1.152.0 do not receive "Saved messages" from 1.154.1 and 1.154.4

[WofWca]

• Operating System (Linux/Mac/Windows/iOS/Android): Desktop

• Delta Chat Version: 1.52.0

• Expected behavior: Sending a message to "Saved Messages" makes it appear on all devices

• Actual behavior: The message does not appear on the other device, which runs core v1.152.1

• Steps to reproduce the problem:

  1. Install Delta Chat Desktop 1.52.0 (core v1.154.3)
  2. Install Delta Chat Android 1.50.3 (core 1.152.0)
  3. Create an account on Android
  4. Add Desktop as second device
  5. Open "Saved Messages" chat
  6. Type and send a message

• Screenshots:

• Logs:

  12:35:44.628  __ __ 🔵 DeltaChat: [accId=1] src/imap/idle.rs:76: INBOX: Idle has NewData ResponseData { raw: 4096, response: MailboxData(Exists(31)) }
  12:35:44.775  __ __ 🔵 DeltaChat: [accId=1] src/imap.rs:1323: Starting a full FETCH of message set "32".
  12:35:44.847  __ __ 🔵 DeltaChat: [accId=1] src/imap.rs:1436: Passing message UID 32 to receive_imf().
  12:35:44.861  __ __ 🔵 DeltaChat: [accId=1] src/receive_imf.rs:222: Receiving message "<REDACTED>", seen=true...
  12:35:44.867  __ __ 🔵 DeltaChat: [accId=1] src/receive_imf.rs:1239: No chat id for message (TRASH).
  12:35:44.871  __ __ 🔵 DeltaChat: [accId=1] src/receive_imf.rs:1688: Message has 1 parts and is assigned to chat #Chat#Trash.
  12:35:44.874  __ __ 🔵 DeltaChat: [accId=1] src/imap.rs:1478: Successfully received 1 UIDs.
  12:35:44.875  __ __ 🔵 DeltaChat: [accId=1] src/imap.rs:752: 1 mails read from "INBOX".
  12:35:44.948  __ __ 🔵 DeltaChat: [accId=1] src/scheduler.rs:674: IMAP session supports IDLE, using it.
  12:35:44.014  __ __ 🔵 DeltaChat: [accId=1] src/imap/idle.rs:64: INBOX: Idle entering wait-on-remote state
  

bcc self = 1 on both devices.

If I send from Desktop 1.52.0 to Desktop 1.50.1 (core v1.152.1) it also does not receive the message.
Android v1.50.5 receives messages just fine.

Originally reported by @ralphtheninja

[link2xt]

I think the bug is that saved messages have "undisclosed recipients" empty group in the To field now and old core assigns such messages to trash. With 1:1 messages I took care to avoid this so we don't break backwards compatibility, but with saved messages I did not test this.

[r10s]

k, so probably unrelated to just merged add API to save messages - which was suspicious alone by its title 😅

[link2xt]

Made a fix #6469