Fix crash on missing ripemd160 hash function; add troubleshooting guide

[Brian496]

Summary

This PR adds a fallback handler in lbry/crypto/hash.py to gracefully handle environments where the 'ripemd160' hash is not supported by OpenSSL. The fallback prevents a startup crash and prints a helpful error message.

Additionally, a note has been added to the README.md to help users resolve the issue if it occurs, particularly in WSL or custom Python builds.

Changes

• Wrapped hashlib.new('ripemd160') in a try/except block
• Provided troubleshooting info in README.md

Reason

Without this fix, lbrynet crashes at startup with a cryptic ValueError: unsupported hash type ripemd160 in certain environments (e.g., WSL2 with some OpenSSL builds). This addresses that critical error while documenting a workaround.

Related

• Original issue encountered and resolved in testing with Ubuntu 22.04 on WSL2.
• Abandoned PR at Fix crash on missing ripemd160 hash function; add troubleshooting guide lbryio/lbry-sdk#3746 (no active maintainers).

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✅ Happy to iterate if improvements are suggested.

[ben221199]

LTGM.