X4 support broken

[iovsiann]

X4 works with the old EAIBOT code at https://github.com/EAIBOT/ydlidar_arduino
X4 doesn't work with the YDLIDAR code version https://github.com/YDLIDAR/ydlidar_arduino
YDLIDAR code sends incorrect initialization commands to X4.
EAIBOT initialization sequence for X4 is below:

A5 90 Firmware version:1.5.0
A5 92 [YDLIDAR INFO] YDLIDAR running correctly! The health status:well
A5 0 A5 60
// waitScanDot() succeeds

YDLIDAR initialization sequence for X4 is below:

A5 90 Firmware version:1.5.0
A5 91 [YDLIDAR INFO] YDLIDAR running correctly! The health status:well
// waitScanDot() returns error