Improve shuffling algorithm of connection list

Improve shuffling algorithm of connection list

This patch implements the Fisher-Yates shuffle algorithm to ensure that all
permutations of the connection target list are generated with equal
probability, eliminating biases present in the previous shuffling method. In
the Fisher-Yates algorithm, there's only one way to obtain each permutation
through a series of element swaps, so all permutations occur with equal
probability in theory.

Signed-off-by: Shuji Furukawa <shujifurukawa1213@gmail.com>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20241118142019.31045-1-shujifurukawa1213@gmail.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg29837.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>