fix: [stix2 import] Fixed 'from' attribute type mapping for email object
fix: [stix2 import] Fixed 'from' attribute type mapping for email object

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