package/wolfssl: security bump to version 4.8.1

package/wolfssl: security bump to version 4.8.1

- [High] OCSP verification issue when response is for a certificate with
  no relation to the chain in question BUT that response contains the
  NoCheck extension which effectively disables ALL verification of that
  one cert.
- [Low] OCSP request/response verification issue. In the case that the
  serial number in the OCSP request differs from the serial number in
  the OCSP response the error from the comparison was not resulting in a
  failed verification.
- [Low] CVE-2021-24116: Side-Channel cache look up vulnerability in
  base64 PEM decoding for versions of wolfSSL 4.5.0 and earlier.
  Versions 4.6.0 and up contain a fix and do not need to be updated for
  this report.

https://github.com/wolfSSL/wolfssl/blob/v4.8.1-stable/ChangeLog.md

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>