Resizing the widget changes the viewport.

CCBUG: 293148
(cherry picked from commit 2266a469)

src/lib/MarbleWidget.cpp

@@ -717,6 +717,7 @@ void MarbleWidget::resizeEvent( QResizeEvent* )
     setUpdatesEnabled( false );
     d->m_map.setSize( width(), height() );
     d->repaint();
+    emit visibleLatLonAltBoxChanged( d->m_map.viewport()->viewLatLonAltBox() );
     setUpdatesEnabled( true );
 }