How do I toggle the update warning? I recently used drush to update my site. This is the current drush status:

$ drush status
 Drupal version                  :  7.29                  
 Site URI                        :  http://default        
 Database driver                 :  mysql                 
 Database username               :  %$^&amp;*(         
 Database name                   :  %$^&amp;*(         
 Database                        :  Connected             
 Drupal bootstrap                :  Successful            
 Drupal user                     :  Anonymous             
 Default theme                   :  openchurch_theme      
 Administration theme            :  seven                 
 PHP configuration               :  #$%^&amp;*
 PHP OS                          :  Linux                 
 Drush version                   :  6.4-dev               
 Drush configuration             :                        
 Drush alias files               :                        
 Drupal root                     :  #$%^&amp;*  
 Site path                       :  sites/default         
 File directory path             :  sites/default/files   
 Temporary file directory path   :  /tmp                 


But when I visit my admin page, I still get the "You need to upgrade" message. How do I get it to stop?

Here is the update screen:
In this particular case, the issue was that Drupal 7.30 had become available, and the UI of the site was reporting that it had 7.28 installed. This was cached by an out-of-date cache, I believe. Everything was resolved when I updated from 7.29 to 7.30.