Add "Use render output file path" option in compositing File Output node

Given that the only way to get a multilayer EXR out of Blender is a file output node I think there should be a little tickbox option to use the render output path. The way it stands now I have to re-enter in the right folder every time I want to make an iteration to my animation and it would make it way faster to iterate if I could just change the render output folder and the EXR output follows