THE HAGUE, Netherlands (AP) — Appeals judges at the Yugoslav war crimes tribunal on Friday upheld genocide convictions against two senior Bosnian Serbs for their roles in the 1995 Srebrenica massacre, the first final judgment for genocide by the United Nations court. Vujadin Popovic and Ljubisa Beara, convicted of the most serious offense in the war crimes statute, were high-ranking security officers with the Bosnian Serb army that overran Muslim forces and thinly armed U.N.