Setting a new value for "Maximum Upload Size" isn't working unless you clear your browser's cache

Steps to reproduce:

1. Try to upload a file bigger than 32Mb (F1) to a page (P1)
   
2. Go to http://localhost:8080/xwiki/bin/edit/XWiki/XWikiPreferences?editor=object&classname=XWiki.XWikiPreferences&object=0
3. Change the value for "Maximum Upload Size" from 33554432 to 3355443200
4. Save XWiki.XWikiPreferences
5. Try again to upload F1 to P1 - you get the same error
   
6. Hit Ctrl-F5 in your browser to clear the cache
7. Try again to upload F1 to P1 - this time it works
   

Expected results:
On step 5 the upload should work without hitting Ctrl-F5.