nixos/xrdp: use --replace-fail with substituteInPlace (#392206)

    chmod +x $out/startwm.sh

    substituteInPlace $out/xrdp.ini \

      --replace "#rsakeys_ini=" "rsakeys_ini=/run/xrdp/rsakeys.ini" \

      --replace "certificate=" "certificate=${cfg.sslCert}" \

      --replace "key_file=" "key_file=${cfg.sslKey}" \

      --replace LogFile=xrdp.log LogFile=/dev/null \

      --replace EnableSyslog=true EnableSyslog=false

      --replace-fail "#rsakeys_ini=" "rsakeys_ini=/run/xrdp/rsakeys.ini" \

      --replace-fail "certificate=" "certificate=${cfg.sslCert}" \

      --replace-fail "key_file=" "key_file=${cfg.sslKey}" \

      --replace-fail LogFile=xrdp.log LogFile=/dev/null \

      --replace-fail EnableSyslog=true EnableSyslog=false

    substituteInPlace $out/sesman.ini \

      --replace LogFile=xrdp-sesman.log LogFile=/dev/null \

      --replace EnableSyslog=1 EnableSyslog=0 \

      --replace startwm.sh $out/startwm.sh \

      --replace reconnectwm.sh $out/reconnectwm.sh \

      --replace-fail LogFile=xrdp-sesman.log LogFile=/dev/null \

      --replace-fail EnableSyslog=1 EnableSyslog=0 \

      --replace-fail startwm.sh $out/startwm.sh \

      --replace-fail reconnectwm.sh $out/reconnectwm.sh \

    # Ensure that clipboard works for non-ASCII characters

    sed -i -e '/.*SessionVariables.*/ a\