Remove dead code

Closes gh-8305

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/SpringBootWebSecurityConfiguration.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -142,17 +142,6 @@ public class SpringBootWebSecurityConfiguration {
 		}
 	}
 
-	public static List<String> getIgnored(SecurityProperties security) {
-		List<String> ignored = new ArrayList<String>(security.getIgnored());
-		if (ignored.isEmpty()) {
-			ignored.addAll(DEFAULT_IGNORED);
-		}
-		else if (ignored.contains("none")) {
-			ignored.remove("none");
-		}
-		return ignored;
-	}
-
 	// Get the ignored paths in early
 	@Order(SecurityProperties.IGNORED_ORDER)
 	private static class IgnoredPathsWebSecurityConfigurerAdapter