fix: watchdog webhook body variables injector

data/Dockerfiles/watchdog/watchdog.sh

@@ -170,7 +170,7 @@ function notify_error() {
     fi
 
     # Replace subject and body placeholders
-    WEBHOOK_BODY=$(echo ${WATCHDOG_NOTIFY_WEBHOOK_BODY} | sed "s|\$SUBJECT\|\${SUBJECT}|$SUBJECT|g" | sed "s|\$BODY\|\${BODY}|$BODY|")
+    WEBHOOK_BODY=$(echo ${WATCHDOG_NOTIFY_WEBHOOK_BODY} | sed "s/\$SUBJECT\|\${SUBJECT}/$SUBJECT/g" | sed "s/\$BODY\|\${BODY}/$BODY/g")
     
     # POST to webhook
     curl -X POST -H "Content-Type: application/json" ${CURL_VERBOSE} -d "${WEBHOOK_BODY}" ${WATCHDOG_NOTIFY_WEBHOOK}