Sending PMP messages doesn't include new-lines outside of edits

[virtueisdead]

Describe the bug

When you set a PMP and send a message with it, any new line characters will be stripped from the message by the time it is displayed on the timeline. If you edit a PMP message, new lines can still be added.

Reproduction

1. Set a PMP with /usepmp
2. Type a message including a new line character, for example

test
test

3. Send the message

Expected behavior

No response

Platform and versions

1: OS: Linux Mint 22.3, Debian 12, Graphene OS
2: Electron, Ungoogled Chromium, Vanadium
3: 1.11.1 (app.sable.moe)
4: 4d2.org

Additional context

This has been confirmed by other users to happen on other homeservers as well