fix: [sightingdbs:model] Added default value for `timestamp`. Fix #5887
fix: [sightingdbs:model] Added default value for `timestamp`. Fix #5887

MISP/MISP,SteveClement/MISP,MISP/MISP,SteveClement/MISP,MISP/MISP,MISP/MISP,SteveClement/MISP,MISP/MISP,SteveClement/MISP,SteveClement/MISP