blockquote 块和下一行行间距的问题

以下样式是正常的：
```
{% blockquote %}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque hendrerit lacus ut purus iaculis feugiat. Sed nec tempor elit, quis aliquam neque. Curabitur sed diam eget dolor fermentum semper at eu lorem.
{% endblockquote %}

下一行文本

{% blockquote %}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque hendrerit lacus ut purus iaculis feugiat. Sed nec tempor elit, quis aliquam neque. Curabitur sed diam eget dolor fermentum semper at eu lorem.
{% endblockquote %}
```

以下样式会有问题：

```
{% blockquote Seth Godin http://sethgodin.typepad.com/seths_blog/2009/07/welcome-to-island-marketing.html Welcome to Island Marketing %}
Every interaction is both precious and an opportunity to delight.
{% endblockquote %}

下一行文本

{% blockquote Seth Godin http://sethgodin.typepad.com/seths_blog/2009/07/welcome-to-island-marketing.html Welcome to Island Marketing %}
Every interaction is both precious and an opportunity to delight.
{% endblockquote %}
```

1、有可能是第一个 endblockquote 和 “下一行文本”之间没有设置行间距；
2、后一种情况，如果去掉中间的 “下一行文本”，两个 blockquote 会连在一起。

版本：5.0.2

Start with the two blockquote examples in the issue and inspect the documentation's blockquote rendering and styles. Reproduce both cases: a blockquote followed by text, and two attributed blockquotes without intervening text. Done means the spacing is consistent in both cases without blockquotes unexpectedly joining.

Written by the indexing model from the issue text.