Merge pull request #4933 from per1234/remove-libMAD

Remove "libMAD"

Author: umbynos

registry.txt

@@ -7324,7 +7324,6 @@ https://github.com/giocip/ARDUINO_num7.git|Contributed|num7
 https://github.com/Naguissa/uHexLib.git|Contributed|uHexLib
 https://github.com/ErlTechnologies/ERLtechRobotcontrol.git|Contributed|ERLtechRobotcontrol
 https://github.com/Muhammed-jbareen/Alarm.git|Contributed|Alarm
-https://github.com/pschatzmann/arduino-libmad.git|Contributed|libMAD
 https://github.com/pschatzmann/arduino-libsbc.git|Contributed|libsbc
 https://github.com/lhtran114/OnlyTimer.git|Contributed|OnlyTimer
 https://github.com/sinricpro/arduino-renesas-sdk.git|Contributed|SinricPro_Renesas