fix: do not remove session tx id if txMeta empty.

Author: polRk

src/query/query-session-execute.ts

@@ -200,8 +200,6 @@ export function execute(this: QuerySession, args: IExecuteArgs): Promise<IExecut
 
         if (partialResp.txMeta?.id)
             this[sessionTxIdSymbol] = partialResp.txMeta!.id;
-        else
-            delete this[sessionTxIdSymbol];
 
         if (partialResp.resultSet) {