(refs #1357)Fix error page

src/main/twirl/gitbucket/core/error.scala.html

@@ -1,4 +1,8 @@
 @(title: String)(implicit context: gitbucket.core.controller.Context)
 @gitbucket.core.html.main("Error"){
+  <div class="content-wrapper main-center">
+    <div class="content body">
       <h1>@title</h1>
+    </div>
+  </div>
 }