Add Python tests for message forwarding from encrypted to unencrypted chat

[link2xt]

Taking a Message object (dc_msg_t) of incoming message and sending it to another chat should work:
https://git.0x90.space/missytake/teams-bot/src/commit/b899b6c3eb8514d39470c2f7a3eed2acb86ffe81/src/teams_bot/bot.py#L198

Currently it seems not to clear Param::GuaranteeE2ee so if the message has a padlock this param is set but for outgoing message it means that encryption should actually be guaranteed and fails sending if there is no key for some recipient.

[missytake]

So it seems we managed to pin down the issue... do you have an idea which is the latest core version which doesn't force encryption like this? Then I could pin the deltachat version in teams-bot as a quickfix.

[link2xt]

It was always working like this I think.

[missytake]

It was always working like this I think.

no, if the message is forwarded like this, and was encrypted, but not in a protected group, it works - see the test in the first commit of the attached PR, before I made it run in a protected group in the second commit.

[missytake]

ah wait, it was with an unencrypted message, my bad. You are correct, it was always working like this I guess.

[missytake]

Related teams-bot issue: https://git.0x90.space/missytake/teams-bot/issues/16