Some CSS to hide the Site URL and Home URL from the Wordpress settings page. http://git.io/fFVxOA

hide-siteurl-option.php

<?php
add_action('admin_head', 'custom_admin_css');

function custom_admin_css() { ?>
  <style>
  label[for=siteurl], input[name=siteurl], label[for=home], input[name=home], input[name=home] + p.description  {
    display: none;
  }
  </style>
  <?php
}

This can be placed in at theme's functions.php or within a plugin.

For quick implementation without coding, use these steps:

1. Download the PHP file by click clicking the raw icon above (see image) and chosing "Save link as"
2. Upload that file to the wp-content/mu-plugins folder