title: Failed to push some refs to remote repository
body: <p>I create a new remote repository in my LAN and I add the projects （<code>PROJECT 1</code>，<code>PROJECT 2</code>).</p>
  
  <p>USER A and USER B clone the repository at a time and USER A did the changes in <code>PROJECT 1</code> and pushed these changes.</p>
  
  <p>USER B did the changes in <code>PROJECT 2</code>,he didn't make any changes in <code>PROJECT 1</code> and while pushing the data also he select only <code>PROJECT 2</code> content, But it gives error while pushing.</p>
  
  <pre><code>ERROR :
  
  error: failed to push some refs to http://gitbub.com
  hint: Updates were rejected because the remote contains work that you do
  hint: not have locally. This is usually caused by another repository pushing
  hint: to the same ref. You may want to first merge the remote changes (e.g.,
  hint: 'git pull') before pushing again.
  hint: See the 'Note about fast-forwards' in 'git push --help' for details.`
  </code></pre>
  
  <p>How to allow the push for User 2?</p>