hixie: typo (whatwg r5167)

hixie: typo (whatwg r5167)

http://dev.w3.org/cvsweb/html5/spec/Overview.html?r1=1.4122&r2=1.4123&f=h
http://html5.org/tools/web-apps-tracker?from=5166&to=5167

===================================================================
RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.4122
retrieving revision 1.4123
diff -u -d -r1.4122 -r1.4123
--- Overview.html	14 Jul 2010 22:02:32 -0000	1.4122
+++ Overview.html	14 Jul 2010 22:06:50 -0000	1.4123
@@ -59825,7 +59825,7 @@
   <a href="#refsDOMEVENTS">[DOMEVENTS]</a></p>
 
   <p>Between the time an element's start tag is parsed and the time
-  either the element's end tag is parsed on the parser detects a
+  either the element's end tag is parsed or the parser detects a
   well-formedness error, the user agent must act as if the element was
   in a <a href="#stack-of-open-elements">stack of open elements</a>.</p>