Fix missing spaces in docs

[Fabrízio de Royes Mello]

Hi all,

The attached patch just fix missing spaces in documentation of CREATE
SERVER and CREATE USER MAPPING.

Regards,

-- 
Fabrízio de Royes Mello
Consultoria/Coaching PostgreSQL
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diff --git a/doc/src/sgml/ref/create_server.sgml b/doc/src/sgml/ref/create_server.sgml
index eb4ca89..af0a7a0 100644
--- a/doc/src/sgml/ref/create_server.sgml
+++ b/doc/src/sgml/ref/create_server.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
 
  <refsynopsisdiv>
 <synopsis>
-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>' ]
     FOREIGN DATA WRAPPER <replaceable class="parameter">fdw_name</replaceable>
     [ OPTIONS ( <replaceable class="parameter">option</replaceable> '<replaceable class="parameter">value</replaceable>' [, ... ] ) ]
 </synopsis>
diff --git a/doc/src/sgml/ref/create_user_mapping.sgml b/doc/src/sgml/ref/create_user_mapping.sgml
index c2f5278..9719a4f 100644
--- a/doc/src/sgml/ref/create_user_mapping.sgml
+++ b/doc/src/sgml/ref/create_user_mapping.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
 
  <refsynopsisdiv>
 <synopsis>
-CREATE USER MAPPING [IF NOT EXISTS] FOR { <replaceable class="parameter">user_name</replaceable> | USER | CURRENT_USER | PUBLIC }
+CREATE USER MAPPING [ IF NOT EXISTS ] FOR { <replaceable class="parameter">user_name</replaceable> | USER | CURRENT_USER | PUBLIC }
     SERVER <replaceable class="parameter">server_name</replaceable>
     [ OPTIONS ( <replaceable class="parameter">option</replaceable> '<replaceable class="parameter">value</replaceable>' [ , ... ] ) ]
 </synopsis>