Clarify effect of @EnableWebSecurity when Actuator's being used

Closes gh-6490

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -2134,8 +2134,9 @@ will be available under `/system`.
 [[howto-switch-off-spring-boot-security-configuration]]
 === Switch off the Spring Boot security configuration
 If you define a `@Configuration` with `@EnableWebSecurity` anywhere in your application
-it will switch off the default webapp security settings in Spring Boot. To tweak the
-defaults try setting properties in `+security.*+` (see
+it will switch off the default webapp security settings in Spring Boot (but leave the
+Actuator's security enabled). To tweak the defaults try setting properties in
+`+security.*+` (see
 {sc-spring-boot-autoconfigure}/security/SecurityProperties.{sc-ext}[`SecurityProperties`]
 for details of available settings) and `SECURITY` section of
 <<common-application-properties-security,Common application properties>>.

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -2290,9 +2290,9 @@ properties are externalized via
 The default security configuration is implemented in `SecurityAutoConfiguration` and in
 the classes imported from there (`SpringBootWebSecurityConfiguration` for web security
 and `AuthenticationManagerConfiguration` for authentication configuration which is also
-relevant in non-web applications). To switch off the default web security configuration
-completely you can add a bean with `@EnableWebSecurity` (this does not disable the
-authentication manager configuration). To customize
+relevant in non-web applications). To switch off the default web application security
+configuration completely you can add a bean with `@EnableWebSecurity` (this does not
+disable the authentication manager configuration or Actuator's security). To customize
 it you normally use external properties and beans of type `WebSecurityConfigurerAdapter`
 (e.g. to add form-based login). To also switch off the authentication manager configuration
 you can add a bean of type `AuthenticationManager`, or else configure the