DAWIT ENDESHAW\ PRIME Minister Abiy Ahmed on Tuesday replaced the defence minister, his former ally Lemma Megersa, as part of a reshuffle ahead of elections in the heavily divided nation next year. Lemma was replaced by Kenea Yadeta, the former security chief of Oromiya region, Abiy's office said on Twitter. Nine other top officials were also replaced, including the attorney general, his deputy and the mining minister. Abiy has promised to hold the first free and fair elections in Africa's second most populous nation next year, but his democratic reforms have also unleashed ethnic divisions that frequently spill into violence.…