gerrit-send-mail: Make output consistent across systems

gerrit-send-mail: Make output consistent across systems

When writing the file specify encoding and newline, so that
the local settings (like locale) do not change the output.

Change-Id: Id7b4bda38adfbb446bdac635ac5d5207ef3f2f40
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Message-Id: <20240129145756.769-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg28153.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>