I agree with Dan, it looks like the crack can't propagate any further because of the hanger bolt hole. I'd expect that the forces from the axle and racks are supported by the area of the dropout behind the hole, so I wouldn't expect it to break from touring.
I'm no engineer, but I have broken few bikes. I'd ride it, and if it falls apart or bugs me I'd replace the frame which shouldn't be to hard to do in Spain, even on tour. Also, if it does break catastrophically while riding you're only dealing with a severely rubbing tire and wheel, which is usually pretty easy to control.