Update fetch.bs

Co-authored-by: Anne van Kesteren <[email protected]>

Author: noamr

fetch.bs

@@ -6815,7 +6815,7 @@ which is an algorithm that takes no arguments:
  <a for=request>URL</a>, <a lt="URL serializer">serialized</a> with
  [=URL serializer/exclude fragment=] set to true.
 
- <li><p>Increment <var>totalRequestLength</var> by the  <a for=string>length</a> of
+ <li><p>Increment <var>totalRequestLength</var> by the <a for=string>length</a> of
  <var>request</var>'s <a for=request>referrer</a>, <a lt="URL serializer">serialized</a>.
 
  <li><p><a for=list>For each</a> (<var>name</var>, <var>value</var>) of <var>request</var>'s