add license header

Author: Sebastien Stormacq

Examples/MultiSourceAPI/Sources/main.swift

@@ -1,6 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftAWSLambdaRuntime open source project
+//
+// Copyright SwiftAWSLambdaRuntime project authors
+// Copyright (c) Amazon.com, Inc. or its affiliates.
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftAWSLambdaRuntime project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
 import AWSLambdaEvents
 import AWSLambdaRuntime
-import HTTPTypes
 import NIOCore
 
 #if canImport(FoundationEssentials)