correct config use of params (#1102)

Author: jmckenna

en/mapcache/config.txt

@@ -92,7 +92,7 @@ see :ref:`mapcache_sources`).
 
 The name and type attributes are straightforward: `type` is "wms", and `name`
 is the key by which this source will be referenced; `<url>` is the HTTP
-location where the service can be accessed; and `<wmsparams>` is a list of
+location where the service can be accessed; and `<params>` is a list of
 parameters that will be added to the WMS request. You should probably at the
 very least add the FORMAT and LAYERS parameters. By convention(?), WMS
 parameters are uppercase, and you should respect this convention in your