Remove "libMAD"

Author: per1234

registry.txt

@@ -7330,7 +7330,6 @@ https://github.com/pschatzmann/arduino-fdk-aac.git|Contributed|fdk-aac
 https://github.com/pschatzmann/arduino-libhelix.git|Contributed|libhelix
 https://github.com/pschatzmann/arduino-libflac.git|Contributed|libflac
 https://github.com/pschatzmann/arduino-liblame.git|Contributed|libLAME
-https://github.com/pschatzmann/arduino-libmad.git|Contributed|libMAD
 https://github.com/pschatzmann/arduino-libopus.git|Contributed|libopus
 https://github.com/pschatzmann/arduino-libsbc.git|Contributed|libsbc
 https://github.com/pschatzmann/arduino-libvorbis-tremor.git|Contributed|libvorbisidec