Missing valid CTCSS tone 62.5

62.5 tone needs to be added to tone.py

Technically 62.5 isn't a standardized PL tone. Some radios may support it, but others definitely wont, and it could raise errors in the CPS.

What I can do though is make tone validation a warning, rather than making it impossible. Then you would be able to specify whatever potentially invalid tones you wanted, and it would be up to the user to read the warnings and choose their own destiny.