fix: bad assignment logic in middleware.renderHeader

src/middleware/admin.js

@@ -80,7 +80,7 @@ middleware.renderHeader = async (req, res, data) => {
 	templateValues.template[res.locals.template] = true;
 
 	// Normally this should hook be automatically added by middleware.processRender(), but it seems to only be fired for page hooks, and not when called internally.
-	({ templateValues } = await plugins.hooks.fire('filter:admin/header.build', { req, res, templateData: templateValues }));
+	({ templateData: templateValues } = await plugins.hooks.fire('filter:admin/header.build', { req, res, templateData: templateValues }));
 
 	return await req.app.renderAsync('admin/header', templateValues);
 };