title: Updating Ubuntu packages fails to fetch
body: <p>I'm trying to get my ubuntu(14.04LTS) updated, and I failed with this message: </p>
  
  <p>W: Failed to fetch <a href="http://extras.ubuntu.com/ubuntu/dists/trusty/Release" rel="nofollow">this</a>  Unable to find expected entry <code>'main/binary-1386/Packages'</code> in Release file (Wrong sources.list entry or malformed file)</p>
  
  <p>I'm quite sure this should be i386, not 1386, but I have no idea how to fix this ridiculous error.</p>
  
  <p>How should I handle this situation?</p>