The usual way to achieve this is by exporting the GIT_SSL_NO_VERIFY=true. This works for a lot of situations and systems, but there's another way to achieve this behavior. In your .git/config, you can create a new section (if you don't have it already) called http and declare a variable sslVerify and set it to false. Like this:
from .git/config
[http]This way, this particular working copy of the repo won't ever check for valid certificates and you don't have to modify your environment. This is specially useful for Windows devs using repos with Tortoise GIT or the Visual Studio GIT plugin.
sslVerify = false
Hope this helps.