Fix lastinputtime not incrementing if idletime is 0

Due to some misplaced conditions, lastinputtime on player_t was not incrementing if idletime was set to 0. The issue was that the increment logic was guarded this check, preventing it from running if idletime was 0 and thus rendered the field useless in Lua. These checks have now been moved to still allow lastinputtime to increment even if idletime is 0.