fixed memory leak in wxXmlResource introduced when fixing wxVector<> usage (patch #1869602)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51170 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/xrc/xmlres.cpp

@@ -235,6 +235,7 @@ bool wxXmlResource::Unload(const wxString& filename)
         {
             if ( (*i)->File == fnd )
             {
+                delete *i;
                 Data().erase(i);
                 unloaded = true;