title: how to exclude some reg pattern
body: <p>I want to write a regular expression to search out all "http" string and replace it with "https", I use following Reg expression:    </p>
  
  <pre><code>\bhttp\b    
  </code></pre>
  
  <p>but some results are not what I want, for example:    </p>
  
  <pre><code>&lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8"&gt;
  </code></pre>
  
  <p>so how can I exclude this?
  I want to use notepad++ to do this.</p>