Update github.com/miekg/dns to v1.1.15 (#12805)

Update the DNS parser used by packetbeat. This fixes the extended RCODE parsing.

CHANGELOG.next.asciidoc

@@ -149,6 +149,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fixed a memory leak when using process monitoring under Windows. {pull}12100[12100]
 - Improved debug logging efficiency in PGQSL module. {issue}12150[12150]
 - Limit memory usage of Redis replication sessions. {issue}12657[12657]
+- Fix parsing the extended RCODE in the DNS parser. {pull}12805[12805]
 
 *Winlogbeat*
 

NOTICE.txt

@@ -2503,8 +2503,8 @@ SOFTWARE.
 
 --------------------------------------------------------------------
 Dependency: github.com/miekg/dns
-Version: v1.0.8
-Revision: 5a2b9fab83ff0f8bfc99684bd5f43a37abe560f1
+Version: v1.1.15
+Revision: b13675009d59c97f3721247d9efa8914e1866a5b
 License type (autodetected): BSD-3-Clause
 ./vendor/github.com/miekg/dns/LICENSE:
 --------------------------------------------------------------------

packetbeat/tests/system/test_0032_dns.py

@@ -254,6 +254,6 @@ def test_edns_dnssec(self):
         assert o["dns.opt.do"] == True
         assert o["dns.opt.version"] == "0"
         assert o["dns.opt.udp_size"] == 4000
-        assert o["dns.opt.ext_rcode"] == "Unknown 15"
+        assert o["dns.opt.ext_rcode"] == "NOERROR"
         assert len(o["dns.answers"]) == 3
         assert all("ietf.org" in x["name"] for x in o["dns.answers"])