fix(package): sentinèlla: base64 logic

package/sentinèlla/probe.sh

@@ -1,3 +1,6 @@
-#!/bin/dash
+#!/usr/bin/env dash
+set -euo pipefail
+socat -V >/dev/null
+dash -c 'echo ok' >/dev/null
 
-socat -T5 -t5 TCP-LISTEN:"${PORT:-5988}",reuseaddr,fork EXEC:"dash $LOOP_FILE"
+socat -T5 -t5 TCP-LISTEN:"${PORT:-5988}",reuseaddr,fork EXEC:"dash ${LOOP_FILE:-probe-loop}"