refactor(): move condition to filter function

Author: kamilmysliwiec

packages/common/pipes/validation.pipe.ts

@@ -94,11 +94,10 @@ export class ValidationPipe implements PipeTransform<any> {
   }
 
   private stripProtoKeys(value: Record<string, any>) {
-    if (isNil(value)) { return; }
     delete value.__proto__;
     const keys = Object.keys(value);
     keys
-      .filter(key => typeof value[key] === 'object')
+      .filter(key => typeof value[key] === 'object' && value[key])
       .forEach(key => this.stripProtoKeys(value[key]));
   }
 }