fix: [stix import] Fixed custom objects import from external files
fix: [stix import] Fixed custom objects import from external files

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