OverflowError in _disable_insert_blocking when using samples_per_insert=None

[KaleabTessera]

When using samples_per_insert=None, this line returns the following error:

 File "/home/kaleab/anaconda3/envs/dyn-net/lib/python3.9/site-packages/acme/jax/experiments/run_experiment.py", line 75, in run_experiment
    replay_tables, rate_limiters_max_diff = _disable_insert_blocking(replay_tables)
  File "/home/kaleab/anaconda3/envs/dyn-net/lib/python3.9/site-packages/acme/jax/experiments/run_experiment.py", line 296, in _disable_insert_blocking
    max(1, int((rate_limiter_info.max_diff - rate_limiter_info.min_diff) / 2))
OverflowError: cannot convert float infinity to integer

,since rate_limiter_info.max_diff and rate_limiter_info.min_diff are inf, therefore (rate_limiter_info.max_diff - rate_limiter_info.min_diff) / 2) is inf as well.