Removed progress.setWindowFlags() call

I am not sure what this wants, but it seems that doesn't affect
xfce but on kde does the progress bar appear randomly in the screen

without it on both cases it appears at center of screen

qubesmanager/qube_manager.py

@@ -815,9 +815,6 @@ class VmManagerWindow(ui_qubemanager.Ui_VmManagerWindow, QtGui.QMainWindow):
         progress = QtGui.QProgressDialog(
             self.tr("Cloning Qube <b>{0}</b> to <b>{1}</b>...").format(
                 vm.name, clone_name), "", 0, 0)
-        progress.setWindowFlags(QtCore.Qt.Window |
-                                QtCore.Qt.WindowTitleHint |
-                                QtCore.Qt.CustomizeWindowHint)
         progress.setCancelButton(None)
         progress.setModal(True)
         progress.show()