Fix handling of build script in release

jupyterlab/make-release.js

@@ -53,8 +53,8 @@ var text = JSON.stringify(sortPackageJson(data), null, 2) + '\n';
 fs.writeFileSync('./package.json', text);
 
 // Update the build script.
-text = JSON.stringify(sortPackageJson(data), null, 2) + '\n';
 data['scripts']['build'] = 'webpack'
+text = JSON.stringify(sortPackageJson(data), null, 2) + '\n';
 fs.writeFileSync('./package.app.json', text);
 
 // Update our app index file.