fix: [stix2 import] Removed try catch on adding attribute to event
fix: [stix2 import] Removed try catch on adding attribute to event

SteveClement/MISP,FIRSTdotorg/MISP,SteveClement/MISP,Rafiot/MISP,FloatingGhost/MISP,MISP/MISP,FloatingGhost/MISP,FIRSTdotorg/MISP,SteveClement/MISP,Rafiot/MISP,devnull-/MISP,devnull-/MISP,MISP/MISP,devnull-/MISP,devnull-/MISP,SteveClement/MISP,Rafiot/MISP,MISP/MISP,SteveClement/MISP,FIRSTdotorg/MISP,MISP/MISP,FIRSTdotorg/MISP,FloatingGhost/MISP,Rafiot/MISP,MISP/MISP,FloatingGhost/MISP