Sudanese security forces killed a protester Sunday as they cracked down on thousands marching for civilian rule, medics said, taking the number killed since last year’s military coup to at least 79. More than three months after the October 25 takeover led by General Abdel Fattah al-Burhan in the troubled northeast African country, defiant mass rallies demanding a restoration of the transition to civilian rule show few signs of abating. “Blood is the path to freedom,” flag-waving protesters chanted as they marched through the streets of Omdurman, which lies across the Nile River from the capita…