views: exclude clients with no partition in image/restore

Clients cannot have an image restore when no partition configuration
is available.
Shown an error listing all the clients with no partitions.

ogcp/views.py

@@ -943,6 +943,7 @@ def action_image_restore():
             form.image.choices.append((image['id'], image['name']))
 
         part_choices = []
+        empty_clients = []
         for ip in ips:
             r = server.get('/client/setup', payload={'client': [ip]})
             if not r:
@@ -968,12 +969,22 @@ def action_image_restore():
                 choice_value = (disk_id, part_id, part_code, filesystem, part_size)
                 parts.append(choice_value)
 
+            if not parts:
+                empty_clients.append(ip)
+
+            if empty_clients:
+                continue
+
             if not part_choices:  # Use first computer as reference part setup conf
                 part_choices = [part for part in parts]
             elif part_choices != parts:
                 flash(_(f'Computers have different partition setup'), category='error')
                 return redirect(url_for('commands'))
 
+        if empty_clients:
+            flash(_(f'The following clients have not partitions: {" ".join(empty_clients)}'), category='error')
+            return redirect(url_for('commands'))
+
         invalid_part_types = get_invalid_image_partition_types()
 
         for disk_id, part_id, part_code, filesystem, part_size in part_choices: