lab.nexedi.com is now our main domain for git hosting.
lab.nexedi.cn continues to work for backward-compatibility reasons.

/reviewed-by: TrustMe

slapos.core.git moved to lab.nexedi.cn and repository on git.erp5.org
made readonly. Update all referenced to old repository location:

    http://git.erp5.org/repos/slapos.core.git

->

    https://lab.nexedi.cn/nexedi/slapos.core.git

/reviewed-by trustme