Added warning for NodeJS <16 to upgrade to new version.

meshcentral.js

@@ -1231,6 +1231,9 @@ function CreateMeshCentralServer(config, args) {
     obj.StartEx1b = async function () {
         var i;
 
+        // Add NodeJS version warning if needed
+        if (Number(process.version.match(/^v(\d+\.\d+)/)[1]) < 16) { addServerWarning("MeshCentral will require Node v16 or above in the future, your current version is " + process.version + "."); }
+
         // Setup certificate operations
         obj.certificateOperations = require('./certoperations.js').CertificateOperations(obj);