FALCON:296 Unable to update feed for S3 replication

javadoc for getOwner() on FileStatus states the following
```text
  /**
   * Get the owner of the file.
   * @return owner of the file. The string could be empty if there is no
   *         notion of owner of a file in a filesystem or if it could not 
   *         be determined (rare).
```
So I guess it is safe to use blank check