remove proxy domain field

Author: paigecalvert

docs/vendor/licenses-using-builtin-fields.mdx

@@ -73,10 +73,6 @@ The built-in license fields are reserved field names.
       <td>`licenseType`</td>
       <td>A string value that describes the type of the license, which is one of the following: `paid`, `trial`, `dev`, `single-tenant-vendor-managed` or `community`. For more information about license types, see [Managing License Type](licenses-about-types).</td>
     </tr>
-    <tr>
-      <td>`replicatedProxyDomain`</td>
-      <td>The domain used for the Replicated proxy registry. By default, `proxy.replicated.com`. For information about setting a custom domain for the proxy registry, see [Using Custom Domains](/vendor/custom-domains-using).</td>
-    </tr>
 </table>    
 
 ### Install Types