changed bg search img on :focus

on focus the search input has white bg and you cannot see the image
I've added a rule to change the bg image
The image is in the theme
https://github.com/topcoat/theme/commit/5c94d8bec6563b9f0142a5363e0a7009fb20e240#L0R14
But it's not in the latest version so tests will fail until theme
version is bumped