By Ange Kasongo KINSHASA (Reuters) -The government of the Democratic Republic of Congo (DRC) on Thursday refused opposition calls for a re-run of disputed elections, as the main observer mission reported “numerous irregularities” that could undermine some results. Provisional results issued so far from the Dec. 20 general election show President Felix Tshisekedi with a commanding lead, but his opponents have demanded they be annulled, citing widespread issues with the roll-out and tabulation of the vote. The dispute threatens to further destabilise Congo, which is already grappling with a secu…