Fix the stderr ot being logged

(fix https://gitlab.gwdg.de/mpsd-cs/mpsd-software-environments/-/issues/2)

install-mpsd-software-environment.py

@@ -253,7 +253,7 @@ def install_environment(
                 .replace("_mpsd_spack_ver_", f"_{mpsd_release}_")
             )
             subprocess.run(
-                f"bash {spack_setup_script} {' '.join(install_flags)} {toolchain} | tee -a {install_log_file} 2>&1",
+                f"bash {spack_setup_script} {' '.join(install_flags)} {toolchain} 2>&1 | tee -a {install_log_file} ",
                 shell=True,
             )