fix: error in toArrayConfig

If an empty string or undefined is provided the method should not return [], but undefined instead. This way defaults defined in Joi function as expected.

Signed-off-by: Philip Molares <philip.molares@udo.edu>

src/config/utils.ts

@@ -5,9 +5,12 @@
  */
 import { Loglevel } from './loglevel.enum';
 
-export function toArrayConfig(configValue?: string, separator = ','): string[] {
+export function toArrayConfig(
+  configValue?: string,
+  separator = ',',
+): string[] | undefined {
   if (!configValue) {
-    return [];
+    return undefined;
   }
   if (!configValue.includes(separator)) {
     return [configValue.trim()];