add ssd feature to create

v2/models/HardDisk.php

@@ -333,7 +333,7 @@ class HardDisk extends AbstractObject{
         $config = [];
         $config[] = $this->getStorage().":".$this->getSize();
         $fields=['cache','discard','media','replicate','format','backup','mbps_rd','mbps_rd_max',
-            'mbps_wr','mbps_wr_max','iops_rd','iops_rd_max','iops_wr','iops_wr_max', 'iothread'];
+            'mbps_wr','mbps_wr_max','iops_rd','iops_rd_max','iops_wr','iops_wr_max', 'iothread', 'ssd'];
         $this->toConfig($fields, $config);
         $prameters = implode(",", $config);
         return $this->api()->put($this->getPath(), [$this->getId()=>  $prameters]);
@@ -437,4 +437,4 @@ class HardDisk extends AbstractObject{
         }
         return true;
     }
-}
+}