fix: [attackMatrix] only return the result for the last attached galaxy
fix: [attackMatrix] only return the result for the last attached galaxy

If a galaxy is already attached, just skip the message.
(The return value is a string, we don't want to compare the string value for
each galaxy to be attached)

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