* Former PM Keita favoured to win on nationalist ticket
* Concerts in capital ahead of Sunday runoff
* UN dispatches voting material to refugee camps (Adds Keita, Cisse quotes, details)
By Daniel Flynn and Tiemoko Diallo
BAMAKO, Aug 9 (Reuters) - Mali's presidential front-runner wrapped up his campaign on Friday with a promise to restore peace to the West African country scarred by a ...