Bluecoat proxy uses a man in the middle attack to monitor https connections. Git does not like that and will throw an ssl verification error:
$ git pull fatal: unable to access 'https://gitlab.com/ron.smits/javafxspielerei.git/': SSL certificate problem: unable to get local issuer certificate
This can be ignored by using
git config http.sslVerify false
Do not do this lightly!!!