Upgrade guide: Fix a typo

Author: mgol

pages/upgrade-guide/3.5.md

@@ -45,7 +45,7 @@ jQuery 3.5.0 has changed `jQuery.htmlPrefilter` to be an identity function. That
 </div>
 ```
 
-To avoid this, don't use self-closing tags for tags that may have content unless you page runs in XHTML mode. Make sure you're sending a correct mime type: `application/xhtml+xml`; otherwise, your page will really run in HTML mode. 
+To avoid this, don't use self-closing tags for tags that may have content unless your page runs in XHTML mode. Make sure you're sending a correct mime type: `application/xhtml+xml`; otherwise, your page will really run in HTML mode. 
 
 If you're writing a library and you want it to work both in HTML & XHTML modes, remember to use self-closing tags for empty elements, i.e. ones that don't have closing tags in HTML. For example, instead of:
 ```js