[Cosmetic] incorrect print statement

[InfamousSYN]

Raising an issue for a minor cosmetic thing that could lead to confusion instead of a PR for a 1-letter change ; my suggestion is to change hardcoded "s" to "m" at line L257.

• There is a hardcoded "s" in {self.batch_delay}s (L257),
• --batch_delay (L735) is provided in minutes,
• The self.batch_delay is transformed from minutes into seconds at runtime (L527)