Update _config.yml

Author: zhang-nianqiang

_config.yml

@@ -26,7 +26,7 @@ url                      : "https://zhang-nianqiang.github.io" # the base hostna
 baseurl                  : # the subpath of your site, e.g. "/blog"
 repository               : "zhang-nianqiang/zhang-nianqiang.github.io" # GitHub username/repo-name e.g. "mmistakes/minimal-mistakes"
 teaser                   : # path of fallback teaser image, e.g. "/assets/images/500x300.png"
-logo                     : "/assets/images/bio-photo.jpg" # path of logo image to display in the masthead, e.g. "/assets/images/88x88.png"
+logo                     : # path of logo image to display in the masthead, e.g. "/assets/images/88x88.png"
 masthead_title           : # overrides the website title displayed in the masthead, use " " for no title
 breadcrumbs              : # true, false (default)
 words_per_minute         : 200