[j.0] fix crash in 'load recent project' ()

Merging branch 'j.0'  into 'main'.

See merge request !2661

GUI/View/Plotter/ProjectionsPlot.cpp

@@ -130,10 +130,10 @@ void ProjectionsPlot::disconnectItems()
     if (!m_data_item)
         return;
 
-    disconnect(m_data_item, nullptr, this, nullptr);
-    disconnect(m_data_item->axItemX(), nullptr, this, nullptr);
-    disconnect(m_data_item->axItemY(), nullptr, this, nullptr);
-    disconnect(m_data_item->zAxisItem(), nullptr, this, nullptr);
+    disconnect(m_data_item, nullptr);
+    disconnect(m_data_item->axItemX(), nullptr);
+    disconnect(m_data_item->axItemY(), nullptr);
+    disconnect(m_data_item->zAxisItem(), nullptr);
 }
 
 QCPGraph* ProjectionsPlot::graphForItem(const LineItem* item)