replace Preset when saving under the same name

[tjingboem]

i'd like to report a small issue: i saved a Preset a few days ago but decided that the Preset was not finished.
So i made the correct one, saved it under the same name as the incorrect one
and found that the incorrect one with that same name was not overwritten.
imo it is better to overwrite and not have confusion later on which one was the correct one.