No, it doesn't. It makes more sense with Magellan. Galileo never had to argue against the earth being flat, he was arguing against the notion that the sun revolved around the earth. His opponents already took a spherical earth as a given.
Magellan had to persuade his sailors that they wouldn't fall off the end of the world, so it makes far more sense coming from him. I don't know where it came from though, just in theory it would make more sense from an explorer than from an astronomer.
Well, C, I have a bit of doubt it was said at all.
When you find a quote being attributed to different people, I become suspicious.
It is a bit like leo x is supposed to have said something to the effect of "What a wonderful thing this fiction of the christ has been for us." I have never found enough corroboration to use it, for myself, anyway.