Text gadget doesn't shows Japanese texts correctly

Summary

Text gadget doesn't shows Japanese texts correctly.

Steps to Reproduce

1. Enable text-gadget module in Gadget Plugin
2. Add Text gadget on your dashboard
3. Input Japanese texts into "Title" and "HTML" field on the gadget

Expected Results

The Japanese texts are shown correctly like it was in JIRA 6.4.x and the before.

Actual Results

After saving the information you inputted on the gadget, the Title of the gadget was shown as Unicode.
When you try to edit the information again, the Title and HTML in the gadget were also shown as Unicode.

Notes

As I mentioned above, this problem never happened on JIRA 6.4.x and the before.