filter email and instance purpose from telemetry unless we have consent

lib/stats.js

@@ -12,10 +12,10 @@ Stats.instanceData = function (Env) {
         httpUnsafeOrigin: Env.httpUnsafeOrigin,
         httpSafeOrigin: Env.httpSafeOrigin,
 
-        adminEmail: Env.adminEmail,
+        adminEmail: Env.consentToContact? Env.adminEmail: undefined,
         consentToContact: Boolean(Env.consentToContact),
 
-        instancePurpose: Env.instancePurpose, // XXX
+        instancePurpose: Env.instancePurpose === 'noanswer'? undefined: Env.instancePurpose,
     };
 
 /*  We reserve the right to choose not to include instances