adjust styles of Comment component

resource/css/_comment_crowi-plus.scss

@@ -11,7 +11,7 @@
       border: 1em solid transparent;
       border-right-color:#f5f5f5;
       border-left-width: 0;
-      left: 3.5em;
+      left: -1em;
       content: "";
       display: block;
       top: 1.5em;