Add 'cisco-sandbox' to the list of broken resolvers

Author: jedisct1

dnscrypt-proxy/example-dnscrypt-proxy.toml

@@ -785,7 +785,7 @@ format = 'tsv'
 ## The list below enables workarounds to make non-relayed usage more reliable
 ## until the servers are fixed.
 
-fragments_blocked = ['cisco', 'cisco-ipv6', 'cisco-familyshield', 'cisco-familyshield-ipv6', 'cleanbrowsing-adult', 'cleanbrowsing-adult-ipv6', 'cleanbrowsing-family', 'cleanbrowsing-family-ipv6', 'cleanbrowsing-security', 'cleanbrowsing-security-ipv6']
+fragments_blocked = ['cisco', 'cisco-ipv6', 'cisco-familyshield', 'cisco-familyshield-ipv6', 'cisco-sandbox', 'cleanbrowsing-adult', 'cleanbrowsing-adult-ipv6', 'cleanbrowsing-family', 'cleanbrowsing-family-ipv6', 'cleanbrowsing-security', 'cleanbrowsing-security-ipv6']