[calamares] Warnings--

The widget name is used (by moc) to inform the name of the
member variable storing the widget; having a :: in the name
yields a member variable with __ in it. Two _ is reserverd
to the implementation.

src/calamares/DebugWindow.ui

@@ -5,7 +5,7 @@ SPDX-FileCopyrightText: 2015 Teo Mrnjavac <teo@kde.org>
 SPDX-License-Identifier: GPL-3.0-or-later
  </author>
  <class>Calamares::DebugWindow</class>
- <widget class="QWidget" name="Calamares::DebugWindow">
+ <widget class="QWidget" name="DebugWindow">
   <property name="geometry">
    <rect>
     <x>0</x>