You've got the syntax for the scp
-style way of specifying a repository slightly wrong - it has to be:
[user@]host.xz:path/to/repo.git/
... as you can see in the git clone documentation. You should use instead the URL:
[email protected]:/gittest.git
i.e. in the URL you're using, you missed out the :
(colon)
To update the URL for origin you could do:
git remote set-url origin [email protected]:/gittest.git