idviews: error out if appling Default Trust View on hosts

https://fedorahosted.org/freeipa/ticket/4615

Reviewed-By: Martin Kosek <mkosek@redhat.com>

ipalib/plugins/idviews.py

@@ -240,6 +240,12 @@ class baseidview_apply(LDAPQuery):
             # the ipaAssignedIDView to None
             view_dn = None
 
+        if view == 'Default Trust View':
+            raise errors.ValidationError(
+                name=_('ID View'),
+                error=_('Default Trust View cannot be applied on hosts')
+            )
+
         completed = 0
         succeeded = {'host': []}
         failed = {