package/libldns: bump version to 1.7.0

package/libldns: bump version to 1.7.0

Commit https://git.nlnetlabs.nl/ldns/commit/host2str.c?id=f7b3a9700e91f8e46477f335c5aaac7c6cdd8acb
added compatability with openssl 1.1.0 but, at the same time, breaks
build without openssl:

./host2str.c:1934:74: error: unknown type name ‘BIGNUM’
 ldns_print_bignum_b64_line(ldns_buffer* output, const char* label, const BIGNUM* num)

This bump makes openssl a mandatory dependency to circumvent the
problem, we do not gain much by leaving out crypto support in a
sensitive area like dns. The only package using libldns, freeswitch,
selects openssl as well, so we have no use case for having libldns
without openssl support.

--disable-dane-verify is needed until we bump our openssl to 1.1.x.,
this fixes the following configure error:

checking for SSL_get0_dane... no
configure: error: OpenSSL does not support offline DANE verification
(Needed for the DANE-TA usage type).  Please upgrade OpenSSL to version
>= 1.1.0 or rerun with --disable-dane-verify or --disable-dane-ta-usage

Removed patches applied upstream:

0001-bugfix-548-Double-free-for-answers-4096.patch
https://git.nlnetlabs.nl/ldns/commit/?h=release-1.7.x&id=2853eb352b4461e98f2926ace4ea3810cedf4167

0002-whitespace-bug-in-ldns-read-zone.patch
https://git.nlnetlabs.nl/ldns/commit/?h=release-1.7.x&id=d6037a22fbedb8ef3a22de4107e4eaa36840865b

0003-let-doxyparse-output-manpage-generation-issues.patch
https://git.nlnetlabs.nl/ldns/commit/?h=release-1.7.x&id=168ee09a4bf184947798c3ee3ac99b6651470d64

0004-Comment-out-debugging-remnants.patch
https://git.nlnetlabs.nl/ldns/commit/?h=release-1.7.x&id=a0a943d504debb05ce4d62ea81c2d218a6cc8727

0005-Remove-manpage-content-nondeterminicity-warnings.patch
https://git.nlnetlabs.nl/ldns/commit/?h=release-1.7.x&id=a56e48856d519d12f1ef600848f335615467f147

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>