Warnings with TimerInterrupt library

[usr97629238]

Warnings while compiling with this library https://github.com/khoih-prog/TimerInterrupt that aren't happening with the stock 328P core:

C:\...\packages\MiniCore\hardware\avr\3.0.1\cores\MCUdude_corefiles/Arduino.h: In instantiation of 'decltype (((b < a) ? b :  a)) min(const T&, const L&) [with T = long int; L = long unsigned int; decltype (((b < a) ? b :  a)) = long unsigned int]':
C:\...\libraries\TimerInterrupt\src/TimerInterrupt.hpp:401:70:   required from here
C:\...\packages\MiniCore\hardware\avr\3.0.1\cores\MCUdude_corefiles/Arduino.h:315:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   return (b < a) ? b : a;
          ~~~^~~~