fix: 更新issue模板中支持链接为邮件格式

Author: SweetWuXiaoMei

.github/ISSUE_TEMPLATE/config.yml

@@ -1,7 +1,7 @@
 blank_issues_enabled: false
 contact_links:
   - name: "Contact Support"
-    url: "dev@servicecomb.apache.org"
+    url: "mailto:dev@servicecomb.apache.org"
     about: "If you need help, please contact us."
 templates:
   - name: "Bug Report"