ssl_mbedtls: Fix format string in get_ssl_library_version

ssl_mbedtls: Fix format string in get_ssl_library_version

These are unsigned values, so treat them as such.

Identified by cppcheck.

Change-Id: I232fba91cfcca6c35d37696bc86890a366f5967f
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1626
Message-Id: <20260414055927.17252-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg36607.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>