verify: revert auto guess. let's be explicit here. just double check for nxdomain

cdn-testlist.txt

@@ -2,4 +2,8 @@ a1.cdn-hotels.com
 cdn.jsdelivr.net
 edge.yunjiasu.com
 ns1.8844dns.com
-www.azure.cn.mschcdn.com
\ No newline at end of file
+www.azure.cn.mschcdn.com
+www.gov.cn
+www.igoldhk.com
+www.travelsky.net
+www.xiumu.org
\ No newline at end of file

verify.py

@@ -118,15 +118,12 @@ class ChinaListVerify(object):
             except (dns.resolver.NoAnswer, dns.resolver.NXDOMAIN, dns.resolver.NoNameservers, dns.exception.Timeout):
                 pass
 
-        # Try to resolve the "homepage" as CDNList, ignore failures
-        else:
-            try:
-                self.check_cdnlist("www." + domain)
-            except (dns.resolver.NoAnswer, dns.resolver.NXDOMAIN, dns.resolver.NoNameservers, dns.exception.Timeout, CDNListNotVerified):
-                pass
-
         if nxdomain:
-            raise NXDOMAIN
+            # Double check due to false positives
+            try:
+                dns.resolver.query("www." + domain, 'A')
+            except dns.resolver.NXDOMAIN:
+                raise NXDOMAIN
 
         self.check_blacklist(nameservers)