Fix EnableWebFluxSecurityTests

Fixes gh-4604

config/src/test/java/org/springframework/security/config/annotation/web/reactive/EnableWebFluxSecurityTests.java

@@ -187,7 +187,7 @@ public class EnableWebFluxSecurityTests {
 			}
 
 			@Bean
-			public PasswordEncoder passwordEncoder() {
+			public static PasswordEncoder passwordEncoder() {
 				return new BCryptPasswordEncoder();
 			}
 		}