If you clone your project on another computer and try to do:

git push origin master

and you get and error like:

fatal: could not read Username for ‘https://github.com’: No such file or directory

then you can solve this by executing the following command:

git remote set-url origin [email protected]:username/repo.git

where, of course,username  and repo  depend on your settings.

For more info, check this StackOverflow question.