mdiag.sh can produce invalid JSON

[adamchel]

I was working with some mdiag.sh output and one of the files contained the following JSON document where "[ESC]" was actually an 0x1B control character.

{
    "ref" : "",
    "host" : "REDACTED",
    "tag" : { "$date" : "2017-09-11T12:50:32.323-0400" },
    "version" : "2.0.4",
    "section" : "timedatectl",
    "ts" : {
        "start" : { "$date" : "2017-09-11T12:51:22.987-0400" },
          "end" : { "$date" : "2017-09-11T12:51:23.015-0400" } },
    "command" : [ "timedatectl" ],
    "rc" : 0,
    "output" : [
        "      Local time: Mon 2017-09-11 12:51:23 EDT",
        "  Universal time: Mon 2017-09-11 16:51:23 UTC",
        "        RTC time: Mon 2017-09-11 12:51:23",
        "       Time zone: America/New_York (EDT, -0400)",
        "     NTP enabled: yes",
        "NTP synchronized: yes",
        " RTC in local TZ: yes",
        "      DST active: yes",
        " Last DST change: DST began at",
        "                  Sun 2017-03-12 01:59:59 EST",
        "                  Sun 2017-03-12 03:00:00 EDT",
        " Next DST change: DST ends (the clock jumps one hour backwards) at",
        "                  Sun 2017-11-05 01:59:59 EDT",
        "                  Sun 2017-11-05 01:00:00 EST",
        "",
        "[ESC]�[1;39mWarning: The system is configured to read the RTC time in the local time zone.",
        "         This mode can not be fully supported. It will create various problems",
        "         with time zone changes and daylight saving time adjustments. The RTC",
        "         time is never updated, it relies on external facilities to maintain it.",
        "         If at all possible, use RTC in UTC by calling",
        "         'timedatectl set-local-rtc 0'�[ESC][0m." ],
    "error" : null
}

Per the JSON specification, control characters are not allowed in strings, so this could probably be fixed by just having the script omit control characters from the JSON output.