Enhance readability when accessing static members

The sole purpose of a few objects was calling a static member of the
class they belonged to. This is not needed, as you can access a static
member with the <class_name>::<member_name> notation.

src/gui/entry/EditEntryWidget.cpp

@@ -1311,8 +1311,7 @@ void EditEntryWidget::pickColor()
         oldColor = QColor(m_advancedUi->bgColorButton->property("color").toString());
     }
 
-    QColorDialog colorDialog(this);
-    QColor newColor = colorDialog.getColor(oldColor);
+    QColor newColor = QColorDialog::getColor(oldColor);
     if (newColor.isValid()) {
         setupColorButton(isForeground, newColor);
         setUnsavedChanges(true);