Fix missing translation contexts

Change-Id: I4402157e7991ad0050333a34394b87ff3d6f4a1b
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Robert Loehning <robert.loehning@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cppcheck/cppcheckoptions.cpp

@@ -47,6 +47,7 @@ namespace Internal {
 
 class OptionsWidget final : public QWidget
 {
+    Q_DECLARE_TR_FUNCTIONS(CppcheckOptionsPage)
 public:
     explicit OptionsWidget(QWidget *parent = nullptr)
         : QWidget(parent),