package/wolfssl: security bump to version 4.7.0

package/wolfssl: security bump to version 4.7.0

Fix CVE-2021-3336: DoTls13CertificateVerify in tls13.c in wolfSSL before
4.7.0 does not cease processing for certain anomalous peer behavior
(sending an ED22519, ED448, ECC, or RSA signature without the
corresponding certificate). The client side is affected because
man-in-the-middle attackers can impersonate TLS 1.3 servers.

https://github.com/wolfSSL/wolfssl/releases/tag/v4.7.0-stable

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>