[Watchdog] Increase threshold for cert check

data/Dockerfiles/watchdog/watchdog.sh

@@ -483,7 +483,7 @@ dovecot_repl_checks() {
 cert_checks() {
   err_count=0
   diff_c=0
-  THRESHOLD=1
+  THRESHOLD=7
   # Reduce error count by 2 after restarting an unhealthy container
   trap "[ ${err_count} -gt 1 ] && err_count=$(( ${err_count} - 2 ))" USR1
   while [ ${err_count} -lt ${THRESHOLD} ]; do