No debug symbols in RelWithDebInfo mode under Linux

[Nekrolm]

I try to build module using pybind11 extension for CMake.
And there are no debug symbols in produced binaries in RelWithDebInfo CMake configuration.

I suppose,a problem in this part of the script. strip is disabled only in Debug mode.

[wjakob]

What happens if you replace Debug by (Debug|RelWithDebInfo)? If that fixes it, could you submit a PR?

[Nekrolm]

Yes. It solves problem.
#1892