title: resetting conda channel priorities
body: <p>I am having issues with conda. After running commands such as:</p>
  
  <pre><code>conda install -c /my_conda_channel numpy --offline --override-channels
  </code></pre>
  
  <p>the default conda channel has now become 'my_conda_channel' so that each subsequent package from this channel supercedes the default channel, which is not what I want. I did the former just for testing purposes.</p>
  
  <p>How do I reset the channel behaviour?</p>