修正stat计数不对的问题

git-svn-id: http://code.alibabatech.com/svn/druid/trunk@255 b9813039-fb51-4c41-a8b9-e21c2acb5095

src/main/java/com/alibaba/druid/stat/JdbcConnectionStat.java

@@ -61,6 +61,7 @@ public class JdbcConnectionStat implements JdbcConnectionStatMBean {
         lastErrorTime = 0;
         lastSampleTime = 0;
 
+        count.set(0);
         closeCount.set(0);
         commitCount.set(0);
         rollbackCount.set(0);