create_server无实质性变化

[jingsam]

diff结果如下，不需要翻译，已经在wiki中更新了翻译进度。

➜  pgdoc-cn git:(master) diff ../postgresql-10.1_std/ref/create_server.sgml ../postgresql-11.2/doc/src/sgml/ref/create_server.sgml
6c6
< <refentry id="SQL-CREATESERVER">
---
> <refentry id="sql-createserver">
24c24
< CREATE SERVER [IF NOT EXISTS] <replaceable class="parameter">server_name</replaceable> [ TYPE '<replaceable class="parameter">server_type</replaceable>' ] [ VERSION '<replaceable class="parameter">server_version</replaceable>' ]
---
> CREATE SERVER [ IF NOT EXISTS ] <replaceable class="parameter">server_name</replaceable> [ TYPE '<replaceable class="parameter">server_type</replaceable>' ] [ VERSION '<replaceable class="parameter">server_version</replaceable>' ]

[ChenHuajun]

大小写和空格的差异也需要反映到sgml里，麻烦提一个PR

[jingsam]

#240