fix KDE4 build

after 72edb696 "loplugin:unusedmethods in vcl"

Change-Id: I15d884b39b38da80bcf10ca81161d0dcb5683954
diff --git a/include/vcl/salnativewidgets.hxx b/include/vcl/salnativewidgets.hxx
index b2dd626..dea3579 100644
--- a/include/vcl/salnativewidgets.hxx
+++ b/include/vcl/salnativewidgets.hxx
@@ -447,6 +447,7 @@ class VCL_DLLPUBLIC TabitemValue : public ImplControlValue
        bool isBothAligned() const  { return isLeftAligned() && isRightAligned(); }
        bool isNotAligned() const   { return !(mnAlignment & (TabitemFlags::LeftAligned | TabitemFlags::RightAligned)); }
        bool isFirst() const        { return bool(mnAlignment & TabitemFlags::FirstInGroup); }
        bool isLast() const         { return bool(mnAlignment & TabitemFlags::LastInGroup); }
        const Rectangle& getContentRect() const { return maContentRect; }
};