Fix COSE algorithm value for ES256K

[pinzolo]

What is this PR for?

This PR will fix invalid COSE algorithm value.

Overview or reasons

Accoding to IANA CBOR Object Signing and Encryption (COSE) Algorithms Registry, the value of ES256K is -47. But the code defines it as -43.

Tasks

I changed the value in production code and test code, and ran tests.

Result

Tests were success.