Sending a request with `max_upcoming_hours` set to 0 returns all upcoming livestreams

[ColdVolcano]

When a request is sent to /live and the max_upcoming_hours parameter is set to 0 all upcoming livestreams will be sent in the upcoming part of the response. Expected result would be to not return any upcoming events, however if 0 is treated as "no filter" it should be documented as such. Aditionally, sending a negative value will omit live events that started between current time and specified value, expected result would probably be a 400 error.