Axivion: Fix reaction on setting changes

While refactoring the signal got lost, bring it back.

Change-Id: I6b7d2764a5acc390c189b8d0000adc74ee2a4a9c
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/axivion/axivionsettings.cpp

@@ -261,6 +261,7 @@ AxivionSettingsWidget::AxivionSettingsWidget()
 void AxivionSettingsWidget::apply()
 {
     settings().server = m_dashboardDisplay->dashboardServer();
+    emit settings().changed(); // ugly but needed
     settings().toSettings();
 }