Fix public domain configuration

Author: wilr

_config/assets.yml

@@ -14,7 +14,7 @@ SilverStripe\Core\Injector\Injector:
     constructor:
       connectionUrl: '`AZURE_CONNECTION_URL`'
       containerName: '`AZURE_CONTAINER_NAME`'
-      assetDomain: '`AZURE_CONTAINER_NAME`'
+      assetDomain: '`AZURE_PUBLIC_BLOB_DOMAIN`'
   League\Flysystem\Cached\Storage\Memory.public:
     class: League\Flysystem\Cached\Storage\Memory
   League\Flysystem\Cached\Storage\Adapter.public:

src/Adapter/PublicAdapter.php

@@ -24,7 +24,7 @@ public function __construct($connectionUrl = '', $containerName = '', $assetDoma
 
         $client = BlobService::clientForConnection($connectionUrl);
 
-        if ($assetDomain) {
+        if ($assetDomain && !empty($assetDomain)) {
             $this->assetDomain = $assetDomain;
         } else {
             $this->assetDomain = (string) BlobService::getClient()