outgoing long text message has "show full message" button but "full message" is empty

[adbenitez]

a blank screen is show when you press "show full message" from an outgoing message you just sent from your current device, also when forwarding it, the message is forwarded truncated without the "show full message" button

this is probably due to https://github.com/deltachat/deltachat-core-rust/pull/5964 not working as expected