Fix wxMSW compilation in STL build after the changes of r72472,

Call t_str() to explicitly convert wxString to wxChar* as implicit conversion
is not available in STL build.

Closes #14666.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72504 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/translation.cpp

@@ -1950,7 +1950,7 @@ wxMsgCatalog *wxResourceTranslationsLoader::LoadCatalog(const wxString& domain,
 
     if ( !wxLoadUserResource(&mo_data, &mo_size,
                              resname,
-                             GetResourceType(),
+                             GetResourceType().t_str(),
                              GetModule()) )
         return NULL;