Improved testing of empty variables in the startup container script.
Improved testing of empty variables in the startup container script.

Node-DC/Node-DC-SSR,egalli/Node-DC-EIS,Node-DC/Node-DC-EIS,egalli/Node-DC-EIS,Node-DC/Node-DC-SSR,Node-DC/Node-DC-EIS,egalli/Node-DC-EIS,Node-DC/Node-DC-EIS,egalli/Node-DC-EIS,Node-DC/Node-DC-EIS