Hue's application bar may disappear on upgrade from CDH3b3 -> CDH3u0

This bug will only happen for users who have the Beeswax window open before upgrade to CDH3u0.

The Hue from CDH3b3 has the potential to write out malformed JSON into the desktop_userpreferences table. Specifically, it truncates the info restoring the Beeswax window. When this attempts to get loaded at login in bootstrap.js, we just blindly inject the data, and we end up with a syntax error in bootstrap.js, which prevents the application bar from loading.

The work-around is:

1. Log in to the Hue database.
2. DELETE FROM desktop_userpreferences WHERE key = 'state';