fix：'begin'，the sql that follows commits implicitly(inner 867)

src/main/java/com/actiontech/dble/services/BusinessService.java

@@ -11,6 +11,7 @@ import com.actiontech.dble.server.variables.MysqlVariable;
 import java.util.concurrent.atomic.AtomicLong;
 
 public abstract class BusinessService extends FrontEndService {
+    protected volatile boolean txChainBegin;
     protected volatile boolean txStarted;
     protected final AtomicLong queriesCounter = new AtomicLong(0);
     protected final AtomicLong transactionsCounter = new AtomicLong(0);
@@ -25,7 +26,11 @@ public abstract class BusinessService extends FrontEndService {
     }
 
     public void setTxStart(boolean txStart) {
-        this.txStarted = txStart;
+        if (!txStart && txChainBegin) {
+            txChainBegin = false;
+        } else {
+            this.txStarted = txStart;
+        }
     }
 
     public void queryCount() {

src/main/java/com/actiontech/dble/services/mysqlsharding/ShardingService.java

@@ -72,7 +72,6 @@ public class ShardingService extends BusinessService {
     private final MySQLShardingSQLHandler shardingSQLHandler;
 
     protected String executeSql;
-    private volatile boolean txChainBegin;
     private volatile boolean txInterrupted;
     private volatile String txInterruptMsg = "";
 
@@ -615,14 +614,6 @@ public class ShardingService extends BusinessService {
         TraceManager.sessionStart(this, "sharding-server-start");
     }
 
-    public boolean isTxChainBegin() {
-        return txChainBegin;
-    }
-
-    public void setTxChainBegin(boolean txChainBegin) {
-        this.txChainBegin = txChainBegin;
-    }
-
     public boolean isTxInterrupted() {
         return txInterrupted;
     }

src/main/java/com/actiontech/dble/services/rwsplit/RWSplitService.java

@@ -261,6 +261,11 @@ public class RWSplitService extends BusinessService {
         return expectedDest;
     }
 
+    @Override
+    public void setTxStart(boolean txStart) {
+        this.txStarted = txStart;
+    }
+
     @Override
     public void killAndClose(String reason) {
         session.close(reason);