NAIROBI, Kenya — Gunmen in central Somalia on Dec. 8 killed an underground Christian who had been receiving death threats for leaving Islam, area sources said. Two unidentified, masked men shot Mursal Isse Siad, 55, outside his home in Beledweyne, 206 miles north of Mogadishu, for leaving Islam, Muslim and Christian sources told Morning Star News. The assailants fled immediately…