You have moved your gitolite server or you want to be able to access your gitolite server behind a firewall and port 22 for ssh is no longer available.
Edit your .git/config file and replace the line with :
url = git_user_name@http://server_ip:repo_name.git
to the following:
url = ssh://git_user_name@external_ip:non_standard_ssh_port/repo_name.git