Admin bar in backend borked on activation

[andrea_r]

Upon activation of today's trunk (rev 2205), the admin bar in the backend is displaced & unstyled as soon as the plugin is activated.

As son as a proper BP-enabled theme is activated, this goes away, but this is probably to confuse people at best, or mislead them into thinking it's broken at worst.

To reproduce, just go activate kubrick. :) Scroll down.

[andrea_r]

Gah, typos without proofreading above, sorry.

"As soon as" and "but this will probably"

[apeatling]

(In [2206]) Fixes #1478