python-pyRFC3339 from home:bigironman:Backports:SLE-15-SP6 project

需要 15.6 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:bigironman:Backports:SLE-15-SP6/15.6/home:bigironman:Backports:SLE-15-SP6.repo
zypper refresh
zypper install python-pyRFC3339