when DubboConfigConfigurationRegistrar do registerBeans have unreasonable use

[IronCity]

The problem happened in
dubbo-spring-boot-project branch 2.7.x
dubbo 2.7.1

class : DubboConfigConfigurationRegistrar

        // Single Config Bindings
        registerBeans(registry, DubboConfigConfiguration.Single.class);

        if (multiple) { // Since 2.6.6 https://github.com/apache/incubator-dubbo/issues/3193
            registerBeans(registry, DubboConfigConfiguration.Multiple.class);
        }

I found class DubboAutoConfiguration default Multiple,

    @ConditionalOnProperty(prefix = DUBBO_CONFIG_PREFIX, name = MULTIPLE_CONFIG_PROPERTY_NAME, matchIfMissing = true)
    @EnableDubboConfig(multiple = true)
    protected static class MultipleDubboConfigConfiguration {
    }

when matchIfMissing = true, MultipleDubboConfigConfiguration will run, will error by spring

Invalid bean definition with name 'dubboConfigConfiguration.Multiple' defined in null: Cannot register bean definition [Generic bean: class [org.apache.dubbo.config.spring.context.annotation.DubboConfigConfiguration$Multiple]; scope=singleton; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null] for bean 'dubboConfigConfiguration.Multiple': There is already [Generic bean: class [org.apache.dubbo.config.spring.context.annotation.DubboConfigConfiguration$Multiple]; scope=singleton; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null] bound.

but dubbo 2.7.0 is difference, it will not happen, code as following shows

        if (multiple) { //true
            registerBeans(registry, DubboConfigConfiguration.Multiple.class);
        } else {
            registerBeans(registry, DubboConfigConfiguration.Single.class);
        }

I want to use dubbo 2.7.1 and dubbo-spring-boot-project 2.7.x, I hope not need to add config

dubbo.config.multiple=false

[mercyblitz]

@see apache/dubbo#3193