libstdc++6 from home:MaxxedSUSE:testing project

需要 openSUSE Tumbleweed ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:MaxxedSUSE:testing/openSUSE_Tumbleweed/home:MaxxedSUSE:testing.repo
zypper refresh
zypper install libstdc++6