add: [stix1 export] Added x509 Certificate STIX object namespaces
add: [stix1 export] Added x509 Certificate STIX object namespaces

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