Feature/retrieve registered users (#243)

* add GET /Accounts/:sid/RegisteredSipUsers

* fix vulnerabilities

lib/helpers/realtimedb-helpers.js

@@ -25,6 +25,7 @@ const JAMBONES_REDIS_SENTINELS = process.env.JAMBONES_REDIS_SENTINELS ? {
 } : null;
 
 const {
+  client,
   retrieveCall,
   deleteCall,
   listCalls,
@@ -42,6 +43,7 @@ const {
 }, logger);
 
 module.exports = {
+  client,
   retrieveCall,
   deleteCall,
   listCalls,