Cleanup unused import

config/src/main/kotlin/org/springframework/security/config/web/server/ServerPermissionsPolicyDsl.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,6 @@
 
 package org.springframework.security.config.web.server
 
-import org.springframework.security.web.server.header.ReferrerPolicyServerHttpHeadersWriter
-
 /**
  * A Kotlin DSL to configure the [ServerHttpSecurity] permissions policy header using
  * idiomatic Kotlin code.