Block fetcher dies randomly

[ryukzak]

Maybe it helps. In branch:

• https://github.com/mlabs-haskell/ogmios-datum-cache/pull/64

Slightly improved error warnings and issue represented in the following way:

• startup: https://github.com/mlabs-haskell/ogmios-datum-cache/blob/3c2b1adf3efbfb382f009cc67962008e9dbde33e/test-env/ogmios-datum-cache-vasil-testnet/README.md
• after request you can see in the console:

[Info#receiveBlocksLoop] Processing block: (49991,Just "d3e00cb7641540efe6153bb58feeef23fd964c35508711793ea47d68d663f955")
[Info#receiveBlocksLoop] Processing block: (50028,Just "b1e2d52c971c9ab78ea604326e32b5c9730f325d5cebcae1dd96825f0e6212b8")
[Info#receiveBlocksLoop] Processing block: (50060,Just "9fa593eb115c9e789caa68f085e1de1d315c8aa3c743d63cbcaed368b5b35f58")
[Info#receiveBlocksLoop] Processing block: (50063,Just "8edc055171107e1a8253fd8cb90c39c50879bbfe5a96acbaa9a64f22dcc5519b")
[Error#ogmiosWorker] Error starting ogmios client: ExceptionInLinkedThread (ThreadId 14) ConnectionClosed