Updated nettle packages fix security vulnerabilities

Remote crash in RSA decryption via manipulated ciphertext (CVE-2021-3580). A flaw was found in Nettle in versions before 3.7.2, where several Nettle signature verification functions (GOST DSA, EDDSA & ECDSA) result in the Elliptic Curve Cryptography point (ECC) multiply function being called with out-of-range scalers, possibly resulting in incorrect results. This flaw allows an attacker to force an invalid signature, causing an assertion failure or possible validation (CVE-2021-20305). The Mageia 8 nettle package has been updated to version 3.7.3 and the Mageia 7 nettle package has been patched to fix these issues.