Make comment form bigger

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/generic/markdown_area.scss

@@ -83,7 +83,7 @@
 .md-preview-holder {
   background: #FFF;
   border: 1px solid #ddd;
-  min-height: 100px;
+  min-height: 169px;
   padding: 5px;
   box-shadow: none;
 }
@@ -108,7 +108,7 @@
 .markdown-area {
   background: #FFF;
   border: 1px solid #ddd;
-  min-height: 100px;
+  min-height: 140px;
   padding: 5px;
   box-shadow: none;
   width: 100%;