title: Pressing 'Enter' in the HTML code cause some redundant margin in the result
body: <p>I have this code:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.block{
    background-color:#ecbbbb;
    Display:inline-block;
    width:50mm;
    height:20mm;
    font-size:10px;
    text-align:center
  }
  .gap{
    background-color:#bc6565; 
    Display:inline-block;
    width:4mm;
    height:20mm;
    font-size:10px;
    text-align:center
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;p&gt;This is true&lt;/p&gt;
  &lt;div style="width:320mm;"&gt;
  &lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;
  &lt;/div&gt;
  
  &lt;p&gt;This is weird (have enter in the HTML code)&lt;/p&gt;
  &lt;div style="width:320mm;"&gt;
  &lt;div class="block"&gt;&lt;/div&gt;
  &lt;div class="gap"&gt;&lt;/div&gt;
  &lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;&lt;div class="gap"&gt;&lt;/div&gt;&lt;div class="block"&gt;&lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>Why pressing <code>Enter</code> in the HTML code cause some redundant margin in the result??
  I am using Google Chrome version <code>61.0.3163.91 (Official Build) (64-bit)</code></p>