message: Faster default-initialization of BLS primitives by re-using the null-hash
diff: @@ -51,7 +51,18 @@ public:
  CBLSWrapper()
  {
  - UpdateHash();
  + struct NullHash {
  + uint256 hash;
  + NullHash() {
  + char buf[_SerSize];
  + memset(buf, 0, _SerSize);
  + CHashWriter ss(SER_GETHASH, 0);
  + ss.write(buf, _SerSize);
  + hash = ss.GetHash();
  + }
  + };
  + static NullHash nullHash;
  + cachedHash = nullHash.hash;
  }
  CBLSWrapper(const CBLSWrapper& ref) = default;
  