🐛 1.修復Gitalk報Error: Cannot read property 'repository' of undefined 的bug

🐛 2.修復評論utterances 在display_mode設置為dark時，仍顯示light主題的bug
🐛 3.修復display_mode設置dark沒有效果的bug
🎨 4.評論增加夜間模式、文章頁判斷,減少不必要的js加載

layout/includes/comments/gitalk.pug

@@ -8,7 +8,7 @@ script.
     admin: ['!{theme.gitalk.admin}'],
     id: md5(decodeURI(location.pathname)),
     language: '!{theme.gitalk.language}',
-    perPage: '!{theme.gitalk.perPage}',
+    perPage: !{theme.gitalk.perPage},
     distractionFreeMode: !{theme.gitalk.distractionFreeMode},
     pagerDirection: '!{theme.gitalk.pagerDirection}',
     createIssueManually: !{theme.gitalk.createIssueManually},
@@ -17,7 +17,11 @@ script.
   gitalk.render('gitalk-container')
 
   function commentCount(n){
-    document.getElementsByClassName('gitalk-comment-count')[0].innerHTML= n
+    try {
+      document.getElementsByClassName('gitalk-comment-count')[0].innerHTML= n
+    } catch (e) {
+      return false
+    }
   }