expand col and remove reply button width

src/client/styles/scss/_comment_growi.scss

@@ -98,7 +98,6 @@
   }
   // reply button
   .btn.btn-comment-reply {
-    width: 120px;
     margin-top: 0.5em;
     border: none;
   }

src/server/views/layout-growi/widget/comments.html

@@ -1,6 +1,6 @@
 <div class="page-comments-row row d-edit-none d-print-none">
 
-  <div class="page-comments col-xl-7 col-lg-9 my-5">
+  <div class="page-comments col-lg-12 my-5">
 
     <h1 class="border-bottom pb-2 mb-3"><i class="icon-fw icon-bubbles"></i> Comments</h1>