Remove unnecessary code

Author: cbaker6

lib/client.js

@@ -680,9 +680,6 @@ module.exports = function (dependencies) {
     }
     await this.closeAndDestroySession(this.session);
     await this.closeAndDestroySession(this.manageChannelsSession);
-    if (this.config.createConnection) {
-      this.config.createConnection = null;
-    }
 
     if (callback) {
       callback();