Fix detection of new JK firmware (32 cells)

[Confushion]

Change detection of new JK firmware (32 cells).

Checking buf[189] is wrong: ,this is the most significant byte of field "Cycle Capacity" and this field will slowly increase in value.

Now we check the least significant byte of field "Nominal Capacity", which is a static field.
This field has value 0 in other fw version.

Fixes issues #209 , #235 , #265

[fl4p]

thanks

[leolionart]

Now the problem is to wrong the battery percentage up to more than 160000%. I had to go back to the previous version to fix this bug

[jariojose]

This change generated many marking errors here in my BMS. Most of them display only null values (zeros).