ESP32 sample code ，run in ESP32 dev kit ,frequency show 0Mhz

[win-ds]

Describe the bug
ESP32 sample code ，run in ESP32 dev kit ,frequency show 0Mhz

find the problem here:
previousFrequency = currentFrequency = rx.getFrequency(); // 获取当前频率

it need to change to :
previousFrequency = currentFrequency = rx.getCurrentFrequency(); // 获取当前频率

[KentuLiveAccount]

actually, based on my brief code study, getCurrentFrequency function is simply returning the frequency remembered by the SI4735 class in the library. getFrequency is the one that actually obtains the frequency set within SI4735 chip itself. so, if getFrequency is returning 0, that means frequency change has not happened (at least yet).