fix only wait for sub-procs on bash versions 5.1 or above

snmpd-oid-daemon.sh

@@ -610,8 +610,12 @@ while :; do
       ps -p $pid >/dev/null && kill -SIGKILL $pid
       rc=137
     else
+      if (( ${BASH_VERSINFO[0]} >= 5 )) && (( ${BASH_VERSINFO[1]} >= 1 )); then
         wait $pid
         rc=$?
+      else
+        rc=0
+      fi
     fi
     echo "gather: $func (PID $pid, FD $fd) exited with rc = $rc" >&$DEBUGLOG
     if (( rc == 0 )) && [ -n "$data" ]; then