iptraf-ng from openSUSE:Backports:SLE-15-SP6:Update project

需要 standard ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/openSUSE:Backports:SLE-15-SP6:Update/standard/openSUSE:Backports:SLE-15-SP6:Update.repo
zypper refresh
zypper install iptraf-ng