title: Can not clone project from gitlab
body: <p>I've lauched a private project named 'project_name' on GitLab.  </p>
  
  <p>But when I try to use "<code>git clone git@gitlab.xyz:user_name/project_name.git</code>" on another server, GitLab informed me to input "<code>git@gitlab.xyz's password</code>".<br>
  After inputing three unknow password, It said "<code>Permission denied (publickey,password,keyboard-interactive)</code>"!   </p>
  
  <p>How Can I Config My Server To Access 'project_name' Successfully?  </p>