Fix error when running min on empty list (#314)
Fix error when running min on empty list (#314)

* Fix error when running min on empty list

Running min on an empty list (which occurs on first episode from `if len(content['timestamps'])==0: continue`) causes it to throw an error

* Update monitor.py

Return 0 for initial_reset_timestamp when no initial_reset_timestamps

Farama-Foundation/Gymnasium,dianchen96/gym,dianchen96/gym,machinaut/gym,Farama-Foundation/Gymnasium,machinaut/gym