Fix typo in postgresql README

plugins/inputs/postgresql/README.md

@@ -30,21 +30,21 @@ _* value ignored and therefore not recorded._
 
 More information about the meaning of these metrics can be found in the [PostgreSQL Documentation](http://www.postgresql.org/docs/9.2/static/monitoring-stats.html#PG-STAT-DATABASE-VIEW)
 
-## Configruation
+## Configuration
 Specify address via a url matching:
 
   `postgres://[pqgotest[:password]]@localhost[/dbname]?sslmode=[disable|verify-ca|verify-full]`
 
 All connection parameters are optional. Without the dbname parameter, the driver will default to a database with the same name as the user. This dbname is just for instantiating a connection with the server and doesn't restrict the databases we are trying to grab metrics for.
-  
+
 A  list of databases to explicitly ignore.  If not specified, metrics for all databases are gathered.  Do NOT use with the 'databases' option.
 
   `ignored_databases = ["postgres", "template0", "template1"]`
-  
+
 A list of databases to pull metrics about. If not specified, metrics for all databases are gathered.  Do NOT use with the 'ignored_databases' option.
 
   `databases = ["app_production", "testing"]`
-  
+
 ### Configuration example
 ```
 [[inputs.postgresql]]