Correct variable name in HTTP-network fetch

Fixes #1283 and closes #1298.

Author: ronag

fetch.bs

@@ -5147,7 +5147,7 @@ optional boolean <var>forceNewConnection</var> (default false), run these steps:
  <li><p>Let <var>timingInfo</var> be <var>fetchParams</var>'s <a for="fetch params">timing info</a>.
 
  <li><p>Let <var>httpCache</var> be the result of <a>determining the HTTP cache partition</a>, given
- <var>httpRequest</var>.
+ <var>request</var>.
 
  <li><p>If <var>httpCache</var> is null, then set <var>request</var>'s <a for=request>cache mode</a>
  to "<code>no-store</code>".