use VCL_DLLPUBLIC for UnoWrapperBase to allow use in vclplug-gtk3

Change-Id: Icecb736088c5c248c1a6bf87ecb8ab0be8e46e00
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/113293
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/include/vcl/toolkit/unowrap.hxx b/include/vcl/toolkit/unowrap.hxx
index 5aea57d..46f1e08 100644
--- a/include/vcl/toolkit/unowrap.hxx
+++ b/include/vcl/toolkit/unowrap.hxx
@@ -43,7 +43,7 @@ namespace com::sun::star::accessibility {
    class XAccessible;
}

class UNLESS_MERGELIBS(VCL_DLLPUBLIC) UnoWrapperBase
class VCL_DLLPUBLIC UnoWrapperBase
{
public:
    virtual void                Destroy() = 0;