Function deltachat::simplify::remove_message_footer

fn remove_message_footer<'a>(
    lines: &'a [&str]
) -> (&'a [&'a str], Option<&'a [&'a str]>)

Remove standard (RFC 3676, §4.3) footer if it is found. Returns (lines, footer_lines) tuple; footer_lines is set to Some if the footer was actually removed from lines (which is equal to the input array otherwise).