message: [tests] fix grep in meshcop
diff: @@ -324,7 +324,7 @@ network_form()
  # verify mDNS is working as expected.
  local mdns_result="${TEST_BASE}"/mdns_result.log
  avahi-browse -aprt | tee "${mdns_result}"
  - OT_BORDER_AGENT_PORT=$(grep "${OT_NETWORK_NAME}" "${mdns_result}" | grep -o ';[0-9]\{5\};' | head -n1 | tr -d ';')
  + OT_BORDER_AGENT_PORT=$(grep -a "${OT_NETWORK_NAME}" "${mdns_result}" | grep -ao ';[0-9]\{5\};' | head -n1 | tr -d ';')
  rm "${mdns_result}"
  }
  