SV4401A firmware v0.3.1 features
Bug fix: 1. Abnormal S21 chart with 'nan' displayed;
            2. Not able to set time and date;


SV4401A v0.3.0固件特性
1. 修复了S21数值显示为“nan”的bug；
2. 修复了无法设置时间和日期的bug；