setup exe used to install Electrum to `C:\Program Files (x86)\Electrum`,
but now as the binaries are amd64, we should install to `C:\Program Files\Electrum`.
With this change, based on my experiments, looks like if there is an existing install,
nsis will keep using that path, but if it's a fresh install, it will now use the 64-bit path.
follow-up fcc4e1d387