Fix JSON output of flarm_decode

[roeles]

http://jsonlint.com/ says about this snippet {"addr":"DDA8B9","time":1490684311.182450,"rssi":-15.1,"channel":117,"lat":54.6552640,"lon":0.1440960,"dist":437095.05,"alt":2415,"vs":-300,"type":7,"stealth":0,"no_track":0,"ns":[3,-104,-37,-91],"ew":[-18,7,5,-89]} {"addr":"DDA8B9","time":1490684311.210040,"rssi":-17.8,"channel":118,"lat":54.6552640,"lon":0.1440960,"dist":437095.05,"alt":2415,"vs":-300,"type":7,"stealth":0,"no_track":0,"ns":[3,-104,-37,-91],"ew":[-18,7,5,-89]} this: Error: Parse error on line 16: ... [-18, 7, 5, -89]} { "addr": "DDA8B9", ----------------------^ Expecting 'EOF', '}', ',', ']', got '{'