Remove vms field from vmhost

Signed-off-by: Nico Schottelius <nico@nico-notebook.schottelius.org>

uncloud/uncloud_vm/models.py

@@ -41,11 +41,9 @@ class VMHost(models.Model):
         max_length=32, choices=STATUS_CHOICES, default=STATUS_DEFAULT
     )
 
-    # List of VMs running on this host
-    vms = models.TextField(default='')
-
-    def get_vms(self):
-        return self.vms.split(',')
+    @property
+    def vms(self):
+        return VMProduct.objects.filter(vmhost=self)
 
 
 class VMProduct(Product):