title: Unable to upgrade Flutter: no origin repository configured
body: <p>I tried to update flutter from this command using cmd:</p>
  
  <pre><code>flutter upgrade
  </code></pre>
  
  <p>And I got:</p>
  
  <pre><code>Unable to upgrade Flutter: no origin repository configured. Run 'git remote add origin https://github.com/flutter/flutter' in C:\flutter
  </code></pre>
  
  <p>What is the reason and how I can solve this?</p>