canna: unsafe handling of /tmp/.iroha_unix directory

A Improper Access Control vulnerability in the systemd service of cana in openSUSE Backports SLE-15-SP3, openSUSE Backports SLE-15-SP4 allows local users to hijack the UNIX domain socket This issue affects: openSUSE Backports SLE-15-SP3 canna versions prior to canna-3.7p3-bp153.2.3.1. openSUSE Backports SLE-15-SP4 canna versions prior to 3.7p3-bp154.3.3.1. openSUSE Factory was also affected. Instead of fixing the package it was deleted there.