Don't allow StatusEffects_gettime to return a time in the past

Don't allow StatusEffects_gettime to return a time in the past

By not doing so the effect would be still active in the last frame even if end time has passed.
It prevents wrong usage of the returned value, for example in Fire_AddDamage where mintime can be set to a negative value and used to apply a negative damage to the player
Removed now redundant max operations at StatusEffects_gettime call sites