[CE-216] Fix host can not delete in admin dashboard

Directly get host type through host model object

Change-Id: Ia39fb70361284ffd051994185737910377f5447b
Signed-off-by: Haitao Yue <hightall@me.com>

src/modules/host.py

@@ -291,7 +291,7 @@ def delete(self, id):
             logger.warning("Cannot delete non-existed host")
             return False
 
-        host_type = h.host.type
+        host_type = h.type
 
         if ClusterModel.objects(host=h).count():
             logger.warning("Host type not found.")