improve dynamic config support for DruidDataSourceStatLogger

src/main/java/com/alibaba/druid/pool/DruidDataSourceStatLoggerAdapter.java

@@ -0,0 +1,18 @@
+package com.alibaba.druid.pool;
+
+import java.util.Properties;
+
+
+public abstract class DruidDataSourceStatLoggerAdapter implements DruidDataSourceStatLogger {
+
+    @Override
+    public void log(DruidDataSourceStatValue statValue) {
+        
+    }
+
+    @Override
+    public void configFromProperties(Properties properties) {
+        
+    }
+
+}