Remove duplicate entry and obsolete one

adonnetworks.com also appears in Prime Visibility (which matches the
staement in the footer of that website: "a PV Media Group company"),
but the other domain, dashboardad.net, doesn't appear to be in use
anymore. None of the hostnames that can be found on Google resolve
anymore.

disconnect-entitylist.json

@@ -920,16 +920,6 @@
             "dmtry.com"
         ]
     },
-    "AdOn Network": {
-        "properties": [
-            "adonnetwork.com",
-            "dashboardad.net"
-        ],
-        "resources": [
-            "adonnetwork.com",
-            "dashboardad.net"
-        ]
-    },
     "AdOnion": {
         "properties": [
             "adonion.com"