Use proper logging message when the synced post is up to date

boards/models/post/sync.py

@@ -194,7 +194,7 b' class SyncManager:'
         version = int(tag_content.find(TAG_VERSION).text)
         is_old = exists and global_id.post.version < version
         if exists and not is_old:
-            print('Post with same ID exists and is up to date.')
+            logger.debug('Post {} exists and is up to date.'.format(global_id))
         else:
             global_id.content = content_str
             global_id.save()