Large block lead to check fail during github tests

When running consensus tests using large block sizes (say 4000+ txs), sometimes the following check fails:
```cpp
void TEDecryptionDB::addDecryptionShares(
    const ::std::shared_ptr< AESKeyDecryptionShareList >& _decryptionShareList ) {
    CHECK_ARGUMENT( _decryptionShareList );
...
```

Meaning the pointer is null.

This issue only happens for onenode test.