* fixed an issue where section style won't be applied

I had an issue with setting the background images for a particular section.
The problem came from the fact that in cellDidLoad you checked whether the tableManager had a custom bg image, but then in layoutSubviews you checked whether the section had a custom bg image - at this point the section has a bg image, but the bg image view was not initialized.

I just rearranged the code a bit, so if in layoutSubviews there is a custom bg image to be set, the view is created at that time.