A call to nc_utils.wait_next_block_factory(eth)() crashes with [Errno 24] Too many open files

[RomanZacharia]

1. Start hydrachain -d datadir runmultiple --num_validators=3 --seed=42
2. Open a console Ctrl+C, Enter
3. Execute calls

from hydrachain.nc_utils import wait_next_block_factory
nc_utils.wait_next_block_factory(eth)() crashes with

The call crashes with the error: [Errno 24] Too many open files