don't use annoying and unneeded in C++ casts of NULL to "T *" in all other files neither

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58227 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk1/region.cpp

@@ -355,7 +355,7 @@ wxRegionContain wxRegion::DoContainsRect(const wxRect& r) const
 GdkRegion *wxRegion::GetRegion() const
 {
     if (!m_refData)
-        return (GdkRegion*) NULL;
+        return NULL;
 
     return M_REGIONDATA->m_region;
 }