dnsrps test no longer runs

The DNSRPS portions of the rpz and rpzrecurse tests were inadvertently disabled some time ago. It doesn't cause a test failure; the only way to know it happened is that "DNSRPS is disabled" appears in the test output. We do have a jenkins system that builds with --enable-dnsrps, but because the test itself thought DNSRPS had been disabled, it was skipped over and nobody was the wiser.

The culprit seems to have been commit b98a9207.