Fix build warnings on MacOS and Linux
Fix build warnings on MacOS and Linux

The workaround to silence false invalid configuration warnings was
effectively only half applied on Unix-based platforms. The issue is that
a semicolon is treated by the shell as a command line separator so
`dotnet msbuild /p:X=Y;Z=W` runs `dotnet msbuild /p:X=Y` then `Z=W`. The
second command is valid and just sets the shell variable Z to W.

nkolev92/sdk,nkolev92/sdk