using a new logger

lib/api/api-router.js

@@ -86,7 +86,7 @@ module.exports = class ApiRouter {
         const mapStore = new windshaft.storage.MapStore({
             pool: redisPool,
             expire_time: serverOptions.grainstore.default_layergroup_ttl,
-            logger: global.logger
+            logger: global.log4js.getLogger('[windshaft]')
         });
 
         const rendererFactory = createRendererFactory({ redisPool, serverOptions, environmentOptions });