title: Rails forms leading to Mixed Content warning
body: <p>In my Rails app I use both Rails' native <code>form_tag</code> method and the <code>simple_form_for</code> method provided by the <a href="https://github.com/plataformatec/simple_form" rel="nofollow noreferrer">simple_form</a> rubygem.</p>
  
  <p>Both of them are leading to the following warning in the chrome console:</p>
  
  <blockquote>
    <p>Mixed Content: The page at '<a href="https://example.com" rel="nofollow noreferrer">https://example.com</a>' was loaded over a secure connection, but contains a form which targets an insecure endpoint '<a href="http://example.com" rel="nofollow noreferrer">http://example.com</a>'. This endpoint should be made available over a secure connection.</p>
  </blockquote>
  
  <p>And indeed, the rendered HTML forms use the <code>http</code> protocol for their <code>action</code> attribute.</p>
  
  <p>What is the reason for that? All my other URL's use the <code>https</code> protocol.</p>