Fix WinMerge dependency on MSVC

[WinMerge](https://apps.0install.net/gui/winmerge.xml) has a dependency on the [Microsoft Visual C++ 2008 Runtime](https://apps.0install.net/lib/msvc90.xml).

This feed dependency is currently not working properly. Probably has to do with how the Windows side-by-side assembly resolution works (may not respect the `PATH` environment variable).