Nano-node: Windows: Old version is not removed after upgrading to a new release

[GoneUp]

Description of bug:
The windows installer of Nano does not replace or remove the old version of the node software. I had this problem on v11 -> v12 and v12 -> v12.1.
It's not a huge deal to deinstall it manually, it's just a bit annoying.

Steps to reproduce the issue:

1. Install a old version of nano
2. Install the current one

Describe the results you received:
Both version are installed afterwards. Present in the file system, start menu and app list.

Describe the results you expected:
Since it's the same software I expect that the old version is removed or upgraded.

Environment:
Windows 10, Version 1709

[argakiig]

Yeah I need to fix the cmake for packaging. It's been on my list of things to do