Ignore non-JSON output in detect-it-easy output

[josh-feather]

The diec binary outputs non-JSON output in JSON mode, causing the parsing to fail. For example:

[!] Heuristic scan is disabled. Use --heuristicscan to enable
{
    "detects": [
        {
            "filetype": "PE64",
            "info": "",
            "offset": "0",
            "parentfilepart": "Header",
            "size": "3488048",
            "values": [
                {
                    "info": "",
                    "name": "Microsoft Linker",
                    "string": "Linker: Microsoft Linker(14.22.27905)",
                    "type": "Linker",
                    "version": "14.22.27905"
                },
                {
                    "info": "C++",
                    "name": "Microsoft Visual C/C++",
                    "string": "Compiler: Microsoft Visual C/C++(19.22.27905)[C++]",
                    "type": "Compiler",
                    "version": "19.22.27905"
                },
                {
                    "info": "",
                    "name": "Visual Studio",
                    "string": "Tool: Visual Studio(2019, v16.2)",
                    "type": "Tool",
                    "version": "2019, v16.2"
                }
            ]
        }
    ]
}

There is a related issue noted against the DIE project:
horsicq/Detect-It-Easy#242