Update Hibernate ORM's "active" documentation

For consistency with datasource documentation.

docs/src/main/asciidoc/hibernate-orm.adoc

@@ -497,8 +497,10 @@ by default it is active at runtime,
 that is Quarkus will start the corresponding Hibernate ORM `SessionFactory` on application startup.
 
 To deactivate a persistence unit at runtime, set `quarkus.hibernate-orm[.optional name].active` to `false`.
-Then Quarkus will not start the corresponding Hibernate ORM `SessionFactory` on application startup.
-Any attempt to use the corresponding persistence unit at runtime will fail with a clear error message.
+If a persistence unit is not active:
+
+* The `SessionFactory` will not start during application startup.
+* Accessing the `EntityManagerFactory`/`EntityManager` or `SessionFactory`/`Session` will cause an exception to be thrown.
 
 This is in particular useful when you want an application to be able
 to xref:datasource.adoc#datasource-active[use one of a pre-determined set of datasources at runtime].

extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/HibernateOrmRuntimeConfigPersistenceUnit.java

@@ -22,10 +22,6 @@ public interface HibernateOrmRuntimeConfigPersistenceUnit {
      *
      * See xref:hibernate-orm.adoc#persistence-unit-active[this section of the documentation].
      *
-     * If the persistence unit is not active, it won't start with the application,
-     * and accessing the corresponding EntityManagerFactory/EntityManager or SessionFactory/Session
-     * will not be possible.
-     *
      * Note that if Hibernate ORM is disabled (i.e. `quarkus.hibernate-orm.enabled` is set to `false`),
      * all persistence units are deactivated, and setting this property to `true` will fail.
      *