Remove trailing whitespace.

Author: cfa

doc/404.pod6

@@ -10,7 +10,7 @@
     <a href="https://github.com/perl6/doc/issues/">on our GitHub repository</a>
     so we can fix it!
     If a search engine sent you here, the link might have disappeared due to site reorganization. We still encourage you to report it as above, but it will eventually disappear from search engines too.
-    If you came following a link from some site or blog, we would still want to know about that; you might want to report the blog or website author too. 
+    If you came following a link from some site or blog, we would still want to know about that; you might want to report the blog or website author too.
 </p>
 
 =end Html