更新 captchaCode

src/assets/js/mixin.js

@@ -58,7 +58,7 @@ export const userMixin = {
     getCaptcha() {
       getCaptchaCode().then(res => {
         if (res.code === 0) {
-          this.captchaCode = 'data:image/jpeg;base64,' + res.data
+          this.captchaCode = res.data
           this.dialogVisible = true
         } else {
           this.message = '获取图形验证码失败, 请重新刷新页面'