BUG/MEDIUM: contrib/spoa: do not register python3.8 if --embed fail

spoa server fails to build when python3.8 is not available. If
python3-config --embed fails, the output of the command is registered in
check_python_config.  However when it's later used to define
PYTHON_DEFAULT_INC and PYTHON_DEFAULT_LIB it's content does not match
and fallback to python2.7

Content of check_python_config when building with python3.6:

  Usage: bin/python3-config --prefix|--exec-prefix|--includes|--libs|--cflags|--ldflags|--extension-suffix|--help|--abiflags|--configdir python3

As we are only looking for return code, this commit ensure we always
ignore the output of python3-config or hash commands.
1 file changed