Previously, "set_draft_raw" function was used with "msg = None" only for
side-effect of removing current draft message in chat.
After draft removal functionality was factored into separate
"maybe_delete_draft" function, it is used directly in only call site,
which used to invoke "set_draft_raw" with optional message.
This function is private, and this refactoring does not change FFI
interface.
Note: This commit fails CI due incorrect formatting. It is done
deliberately to simplify review process.