Fix build with clang

[umq]

I got an error when building validns using clang as CC:

clang -Wall -Werror -pthread -O2 -g -o validns main.o carp.o mempool.o textparse.o base64.o base32hex.o rr.o soa.o a.o cname.o mx.o ns.o rrsig.o nsec.o dnskey.o txt.o aaaa.o naptr.o srv.o nsec3param.o nsec3.o ds.o hinfo.o loc.o nsec3checks.o ptr.o sshfp.o threads.o rp.o spf.o cert.o dname.o tlsa.o nid.o l32.o l64.o lp.o ipseckey.o -L/usr/local/lib -L/opt/local/lib -lJudy -lcrypto
clang: error: argument unused during compilation: '-g'
*** Error code 1

Stop in /usr/ports/dns/validns/work/validns-0.6.

The patch attached fixes the problem.
And I made it simple using suffix rules.

I mistook editing commit log before push, it looks odd :(