Fix bug with GetShardsCount() == 0 (#14812)

Author: dahbka-lis

ydb/core/kqp/common/kqp_tx_manager.cpp

@@ -280,7 +280,7 @@ class TKqpTransactionManager : public IKqpTransactionManager {
     }
 
     bool NeedCommit() const override {
-        const bool dontNeedCommit = IsReadOnly() && (IsSingleShard() || HasSnapshot());
+        const bool dontNeedCommit = IsEmpty() || IsReadOnly() && (IsSingleShard() || HasSnapshot());
         return !dontNeedCommit;
     }