LED matrix does not update with BlueZ 5.50

[larsblumberg]

I've tested this library with BlueZ 4.44 and the LED matrix gets updated with according method calls. However, when using BlueZ 5.50 the LED matrix won't get updated. I've switched forth and back between both versions and could reliably reproduce this bug. This said, BlueZ 5.50 (and maybe even prior versions) are not yet recommended to use. I suspect the bug in this library's dependency at https://github.com/getsenic/gatt-python.