title: Removing hard coded site URL from wp-config
body: <p>After the IP address of my WordPress site had changed, 
  I had to hard code its address in <code>wp-config.php</code>:</p>
  
  <pre><code>define('WP_HOME','http://54.77.99.66');
  define('WP_SITEURL','http://54.77.99.66');
  </code></pre>
  
  <p>When I delete the lines in <code>wp-config.php</code>, my site is no longer accessible.</p>
  
  <p>How can I get rid of the hard coded entries and set my site's address in the UI (which is currently greyed out)?</p>