fix: [opendata export] Using external_baseurl if set, before baseurl
fix: [opendata export] Using external_baseurl if set, before baseurl

- If external_baseurl is not set, baseurl is used

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