fix: streamline foreign resource onDelete strategy validation

Author: kulikp1

adminforth/modules/configValidator.ts

@@ -618,14 +618,10 @@ export default class ConfigValidator implements IConfigValidator {
             errors.push(`Resource "${res.resourceId}" column "${col.name}" isArray is enabled but suggestOnCreate is not an array`);
           }
         }
-        if (col.foreignResource){
-          if (col.foreignResource.onDelete){
-            if (col.foreignResource.onDelete !== 'cascade' && col.foreignResource.onDelete !== 'setNull'){
+        if (col.foreignResource) {
+          if (col.foreignResource.onDelete && (col.foreignResource.onDelete !== 'cascade' && col.foreignResource.onDelete !== 'setNull')){
               errors.push (`Wrong delete strategy you can use 'setNull' or 'cascade'`);
-            }
           }
-        }
-        if (col.foreignResource) {
           if (!col.foreignResource.resourceId) {
             // resourceId is absent or empty
             if (!col.foreignResource.polymorphicResources && !col.foreignResource.polymorphicOn) {