I have a website I am using to host redmine and several git repositories
This works perfectly for http, but I can\'t clone with https, i.e.
git clone htt
XCondE's answer will address the problem, but turning off security warnings always feels like a bad idea. If you're running on an ubuntu box, then the issue may be that the CA certificate for your web server isn't in the /etc/ssl/certs/ca-certificates.crt file. I ran into this with a git server hosted on a web server with a SSL certificate signed by www.incommon.org.
You can add the intermediate certificate to your ca-certificates file, as follows:
wget http://cert.incommon.org/InCommonServerCA.crt
openssl x509 -inform DER -in InCommonServerCA.crt -out incommon.pem
cat /etc/ssl/certs/ca-certificates.crt incommon.pem > ca-certs2.crt
sudo cp /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt.bak
sudo cp ca-certs2.crt /etc/ssl/certs/ca-certificates.crt
There's a good discussion of what's going on behind the scenes here: http://curl.haxx.se/docs/sslcerts.html