Update dnstwist json keynames in core.py

[RomainPisters]

By default dnstwist doesn't work because the if statements in /app/watcher/dns_finder/core.py make references to 'dns-xx' (hyphen) instead of 'dns_xx' (underscore). After applying these changes dnstwist works as expected.

As a test I've added example.com and found the following contents (snippet) being written to /app/watcher/dns_finder/data/list.json:

[
    {
        "dns_a": [
            "93.184.216.34"
        ],
        "dns_aaaa": [
            "2606:2800:220:1:248:1893:25c8:1946"
        ],
        "dns_mx": [
            ""
        ],
        "dns_ns": [
            "a.iana-servers.net"
        ],
        "domain": "example.com",
        "fuzzer": "*original"
    },

[Felix83000]

Hello,

First of all, thank you for your help!

I tested it and you are right, the JSON format just changed in the last release of dnstwist. Hence, it do not work anymore.

I will merge your pull request and create a new release.

Sincerely,
Félix