【GitLab】git cloneできないときの対処方法。[Failed to connect to localhost port 80: Connection refused]が発生した場合

$ git clone http://localhost/testgroup/javaprj.git
Cloning into 'javaprj'...
fatal: unable to access 'http://localhost/testgroup/javaprj.git/': Failed to connect to localhost port 80: Connection refused

$ git clone http://localhost:8888/testgroup/javaprj.git
Cloning into 'javaprj'...
warning: You appear to have cloned an empty repository.