add fallback to http algorithm

Author: carlosjoan91

fetch.bs

@@ -5232,6 +5232,11 @@ these steps:
     <!-- not resetting actualResponse since it's no longer used anyway -->
   </ol>
 
+ <li><p>If <var>response</var> is a <a>network error</a> and <var>request</var> has the
+ <a>https-upgrades</a> flag set, set <var>request</var>'s <a for=/>URL</a> <a for=url>scheme</a>
+ to <code>http</code> and set <var>response</var> to the result of running <a>HTTP-redirect fetch</a>
+ given <var>fetchParams</var> and <var>response</var>.
+
  <li><p>Return <var>response</var>. <span class=note>Typically <var>actualResponse</var>'s
  <a for=response>body</a>'s <a for=body>stream</a> is still being enqueued to after
  returning.</span>