Revert "Add missing license header"

This reverts commit 6937a12.

Author: benesch

src/sqlast/ddl.rs

@@ -1,15 +1,3 @@
-// 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.
-
 //! AST types specific to CREATE/ALTER variants of `SQLStatement`
 //! (commonly referred to as Data Definition Language, or DDL)
 use super::{ASTNode, SQLIdent, SQLObjectName, SQLType};