Use fully qualified domain name in DNS queries

[erkia]

Hi!

SPF checks must be performed on fully qualified domain names (FQDN). This means, that when calling dns_get_record(), domain must end with zero-length label (dot).

Without dot at the end, resolver may search additional domain names, causing unnecessary delays or wrong results. In my case it tries to search .local domain, which tries to resolve non-existent A/AAAA records over mDNS, which causes long delays because of timeouts.

Here is a small pull-request to fix this.

BR,
Erki

[Mika56]

The tests are failing because Symfony's PHPUnit Bridge DnsMock does not "ignore" the trailing dot.
Can you please try to update tests/DNSRecordGetterTest.php and add a trailing dot to each key when calling DnsMock::withMockedHosts?