I've been holding back on this because 1.7.0 requires OpenSSL 1.1.0 or
newer for full DANE support. But we can't wait forever, and nothing in
base uses DANE anyway, so here we go.
Run configure for drill (I forgot to do it when I imported 1.6.17, but the
omission was harmless). Note that running configure --with-drill at the
top level doesn't quite work for us since it is geared toward the slightly
weird upstream Makefiles, which we don't use.
