Read the thread Disable/ Stop “auto-draft” posts on wp-hackers to understand why this is a very bad idea.
Let me quote the explanations from @Otto:
Auto-drafts exist because of the fact that multiple users can create
new posts at the same time. If two people enter post-new at roughly
the same moment, then have their first autosaves occur nearly
simultaneously, then there is a race condition that can cause one of
them to get back the wrong post ID, which will cause a post to be
overwritten/lost when they then continue editing the post.The auto-draft creates the post and gets the ID of the new post before
the editing screen is displayed, thus preventing two simultaneous
authors from accidentally having the same post ID in the data in their
browser.
Auto-drafts are automatically deleted after 7 days of going unused.
They’re self-cleaning, basically. No need to worry about them.They also go away when the first auto-save occurs while writing a new
post.
You should disable the Quick draft on the admin page, because that creates a new auto-draft whenever you load it.
Besides that, you solve a non-existent problem in a way that makes further updates impossible. Stop wasting your valuable time, do something useful instead. 🙂