Description:
------------
When fetching multiple records using dns_get_record; if any of the records return a SERVFAIL; that failure bubbles up; and no result gets returned.

To reproduce this you need a specifically failing dns-server but it's also obvious from the code.

I'd expect an array (with single result) instead of an error when the domain has an A record, but returns a SERVFAIL for AAAA

Test script:
---------------
dns_get_record('domain', DNS_A | DNS_AAAA);

Expected result:
----------------
array(
...
)

Actual result:
--------------
dns_get_record(): A temporary server error occurred. in Command line code on line 1