openssl_compat: Avoid conversion warning for SSL_get_negotiated_group

openssl_compat: Avoid conversion warning for SSL_get_negotiated_group

SSL_get_negotiated_group is documented to return
int and SSL_group_to_name definitely expects an int.

But SSL_get_negotiated_group is actually a macro
implemented by SSL_ctrl, which does return a long.
So to avoid the conversion warning we need the cast.

Change-Id: I31024f93d9d9d0f678fb39d4758a7e870bf00873
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1359
Message-Id: <20251111153230.29865-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg34316.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>