[2436] Proper terminology in comment

src/lib/datasrc/tests/testdata/novalidate.zone

@@ -1,3 +1,3 @@
 .			86400	IN	SOA	a.root-servers.net. nstld.verisign-grs.com. 2010030802 1800 900 604800 86400
-; Missing the NS here, will generate an error in validation
+; Missing the NS here, will generate an error in post-load check of the zone.
 www.       3600    IN   A   192.0.2.1