diff --git a/README.md b/README.md
index 65ddca5b5..33e646494 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,7 @@ The goal of this project is to make the easiest, fastest, and most painless way
 - Repository issues, pull requests and wiki
 - Migrate and mirror repository and its wiki
 - Web editor for repository files and wiki
+- Jupyter Notebook
 - Gravatar and Federated avatar with custom source
 - Mail service
 - Administration panel
@@ -105,6 +106,7 @@ There are 5 ways to install Gogs:
 ## Software and Service Support
 
 - [Drone](https://github.com/drone/drone) (CI)
+- [Jenkins](https://wiki.jenkins-ci.org/display/JENKINS/Gogs+Webhook+Plugin) (CI)
 - [Fabric8](http://fabric8.io/) (DevOps)
 - [Taiga](https://taiga.io/) (Project Management)
 - [Puppet](https://forge.puppetlabs.com/Siteminds/gogs) (IT)
diff --git a/README_ZH.md b/README_ZH.md
index 136d53e6d..262bcbfa9 100644
--- a/README_ZH.md
+++ b/README_ZH.md
@@ -28,6 +28,7 @@ Gogs 的目标是打造一个最简单、最快速和最轻松的方式搭建自
 - 支持迁移和镜像仓库以及它的 Wiki
 - 支持在线编辑仓库文件和 Wiki
 - 支持自定义源的 Gravatar 和 Federated Avatar
+- 支持 Jupyter Notebook
 - 支持邮件服务
 - 支持后台管理面板
 - 支持 MySQL、PostgreSQL、SQLite3 和 [TiDB](https://github.com/pingcap/tidb)（实验性支持） 数据库
@@ -74,6 +75,7 @@ Gogs 的目标是打造一个最简单、最快速和最轻松的方式搭建自
 ## 软件及服务支持
 
 - [Drone](https://github.com/drone/drone)（CI）
+- [Jenkins](https://wiki.jenkins-ci.org/display/JENKINS/Gogs+Webhook+Plugin)（CI）
 - [Fabric8](http://fabric8.io/)（DevOps）
 - [Taiga](https://taiga.io/)（项目管理）
 - [Puppet](https://forge.puppetlabs.com/Siteminds/gogs)（IT）
diff --git a/modules/base/tool.go b/modules/base/tool.go
index 97b605c0c..68257b9ce 100644
--- a/modules/base/tool.go
+++ b/modules/base/tool.go
@@ -181,11 +181,12 @@ func HashEmail(email string) string {
 // which includes app sub-url as prefix. However, it is possible
 // to return full URL if user enables Gravatar-like service.
 func AvatarLink(email string) (url string) {
-	if setting.EnableFederatedAvatar && setting.LibravatarService != nil {
+	if setting.EnableFederatedAvatar && setting.LibravatarService != nil &&
+		len(email) > 0 {
 		var err error
 		url, err = setting.LibravatarService.FromEmail(email)
 		if err != nil {
-			log.Error(4, "LibravatarService.FromEmail [%s]: %v", email, err)
+			log.Error(3, "LibravatarService.FromEmail [%s]: %v", email, err)
 		}
 	}
 	if len(url) == 0 && !setting.DisableGravatar {