chore: add lic header

Signed-off-by: SchrodingerZhu <i@zhuyi.fan>

dbms/src/Storages/DeltaMerge/DeltaTree.ipp

@@ -1,3 +1,16 @@
+// Copyright 2022 PingCAP, Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
 DT_TEMPLATE
 template <class T>
 __attribute__((noinline, flatten)) typename DT_CLASS::InternPtr DT_CLASS::TIFLASH_DT_IMPL_NAME(T * node)