cerbero/vs: Fallback to manual searching when vswhere fails
cerbero/vs: Fallback to manual searching when vswhere fails

If you only have Visual Studio Build Tools installed, vswhere.exe will
be installed by the installer, but it won't find any Visual Studio
instances since it can't find Build Tools installs.

So allow it to fail and fall back to manual searching.

GStreamer/cerbero,nirbheek/cerbero,GStreamer/cerbero,nirbheek/cerbero,GStreamer/cerbero,nirbheek/cerbero,GStreamer/cerbero,GStreamer/cerbero,nirbheek/cerbero