[COVERITY 10932] Properly free jsonObj on error
[COVERITY 10932] Properly free jsonObj on error

Change-Id: I0f48ac7db2533eef3f33a8ffa8e70cc8fa48d826
Reviewed-on: https://gerrit.parrot.biz/55532
Reviewed-by: Maxime Maitre <e46fe1f9761923e97d4fbff83ab76adb16770b5c@parrot.com>

Parrot-Developers/libARDiscovery,Parrot-Developers/libARDiscovery,Parrot-Developers/libARDiscovery,Parrot-Developers/libARDiscovery