Config parsing: Ignore some BIND9-specific resolv.conf options

[adns] / regress / case-unkopts.out

adns debug: using nameserver 172.18.45.6
adns: <supplied configuration text>:5: unknown option `wombat'
adns: <supplied configuration text>:6: unknown configuration directive `stoat'
chiark.greenend.org.uk flags 0 type 1 A(-) submitted
chiark.greenend.org.uk flags 0 type A(-): OK; nrrs=1; cname=$; owner=$; ttl=3600
 212.13.197.229
rc=0