bump mx-chain-core go version.

[cristure]

Reasoning behind the pull request

• Updated proto structure in dependencies.

Proposed changes

• Bump mx-chain-core-go version in go.mod

Testing procedure

• Usual unit tests and PR checks should suffice.

Pre-requisites

Based on the Contributing Guidelines the PR author and the reviewers must check the following requirements are met:

• was the PR targeted to the correct branch?
• if this is a larger feature that probably needs more than one PR, is there a feat branch created?
• if this is a feat branch merging, do all satellite projects have a proper tag inside go.mod?