gtk-builder-tool: Don't break GtkHBox and GtkVBox

These classes have different defaults for ::expand than GtkBox,
which is not reflected in the declared default, so we have to
blacklist it.

gtk/gtk-builder-tool.c

@@ -171,6 +171,8 @@ needs_explicit_setting (MyParserData *data,
     { "GtkWidget", "hexpand", 0 },
     { "GtkWidget", "vexpand", 0 },
     { "GtkContainer", "border-width", 0 },
+    { "GtkVBox", "expand", 1 },
+    { "GtkHBox", "expand", 1 },
     { NULL, NULL, 0 }
   };
   gchar *canonical_name;