Open Replace remote provider's address (#3238)

Author: dabrt

code_samples/back_office/images/config/packages/images_remote.yaml

@@ -3,4 +3,4 @@ ezplatform:
         default:
             provider: remote
             options:
-                url_pattern: 'https://placekitten.com/%%width%%/%%height%%'
+                url_pattern: 'https://placecats.com/%%width%%/%%height%%'

docs/guide/images/images.md

@@ -168,10 +168,10 @@ with basic information about the original image (see [example 1](#configuration-
 With the [`RemoteProvider`](https://github.com/ezsystems/ezplatform-kernel/blob/master/eZ/Bundle/EzPublishCoreBundle/Imagine/PlaceholderProvider/RemoteProvider.php) you can download 
 placeholders from:
 
- - remote sources, for example, <http://placekitten.com> (see [example 2](#configuration-examples))
+ - remote sources, for example, <http://placecats.com> (see [example 2](#configuration-examples))
  - live version of a site (see [example 3](#configuration-examples))
 
-![Placeholder RemoteProvider - placekitten.com](../img/placeholder_remote_provider.jpg "Remote placeholder images on a page")
+![Placeholder RemoteProvider - placecats.com](../img/placeholder_remote_provider.jpg "Remote placeholder images on a page")
 
 |Option|Default value|Description|
 |------|-------------|-----------|