fix: Open up /attributes/index to the API, fixes #2975
fix: Open up /attributes/index to the API, fixes #2975

SteveClement/MISP,Rafiot/MISP,Rafiot/MISP,TheDr1ver/MISP,FIRSTdotorg/MISP,SteveClement/MISP,FIRSTdotorg/MISP,Rafiot/MISP,devnull-/MISP,MISP/MISP,MISP/MISP,TheDr1ver/MISP,MISP/MISP,FIRSTdotorg/MISP,MISP/MISP,devnull-/MISP,SteveClement/MISP,TheDr1ver/MISP,devnull-/MISP,FloatingGhost/MISP,Rafiot/MISP,FIRSTdotorg/MISP,SteveClement/MISP,FloatingGhost/MISP,devnull-/MISP,SteveClement/MISP,FloatingGhost/MISP,FloatingGhost/MISP,MISP/MISP,TheDr1ver/MISP