upgrade version

xxl-job-admin/src/main/java/com/xxl/job/admin/core/util/FtlUtil.java

 import freemarker.ext.beans.BeansWrapperBuilder;
 import freemarker.template.Configuration;
 import freemarker.template.TemplateHashModel;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * ftl util
  * @author xuxueli 2018-01-17 20:37:48
  */
 public class FtlUtil {
+    private static Logger logger = LoggerFactory.getLogger(FtlUtil.class);
 
     private static BeansWrapper wrapper = new BeansWrapperBuilder(Configuration.DEFAULT_INCOMPATIBLE_IMPROVEMENTS).build();     //BeansWrapper.getDefaultInstance();
 
             TemplateHashModel fileStatics = (TemplateHashModel) staticModels.get(packageName);
             return fileStatics;
         } catch (Exception e) {
-            e.printStackTrace();
+            logger.error(e.getMessage(), e);
         }
         return null;
     }

xxl-job-core/src/main/java/com/xxl/job/core/util/XxlJobRemotingUtil.java

                 }
                 return returnT;
             } catch (Exception e) {
-                e.printStackTrace();
+                logger.error(e.getMessage(), e);
                 return new ReturnT<String>(ReturnT.FAIL_CODE, "xxl-rpc remoting response content invalid("+ resultJson +"), for url : " + url);
             }