Fix model name clash in home view
Fix model name clash in home view

Addresses a bug inadvertently introduced in 7db85cb where a second
Category model is imported, causing the code at the bottom of the home
page which renders the top post in the Comment, MP Corner and Advocacy
blog categories to silently fail

hzj123/56th,ken-muturi/pombola,geoffkilpin/pombola,ken-muturi/pombola,ken-muturi/pombola,mysociety/pombola,mysociety/pombola,geoffkilpin/pombola,mysociety/pombola,patricmutwiri/pombola,hzj123/56th,hzj123/56th,patricmutwiri/pombola,ken-muturi/pombola,hzj123/56th,ken-muturi/pombola,geoffkilpin/pombola,mysociety/pombola,mysociety/pombola,patricmutwiri/pombola,geoffkilpin/pombola,ken-muturi/pombola,geoffkilpin/pombola,patricmutwiri/pombola,patricmutwiri/pombola,hzj123/56th,mysociety/pombola,patricmutwiri/pombola,geoffkilpin/pombola,hzj123/56th