fix support drag&drop
fix support drag&drop

mohayonao/timbre.js,eriser/timbre.js,mohayonao/timbre.js,ABaldwinHunter/timbre.js-classic,eriser/timbre.js,ABaldwinHunter/timbre.js,ABaldwinHunter/timbre.js,ABaldwinHunter/timbre.js-classic