### Environment

* Dubbo version: 2.7.3
* Operating System version: win 10
* Java version: 1.8

系统启动时报
Caused by: java.lang.IllegalArgumentException: Unsupported generic type false
	at org.apache.dubbo.config.ServiceConfig.setGeneric(ServiceConfig.java:1015)

这个错误只有在2.7.3的时候存在，在使用2.7.2的时候没有
/**
     * Check if service provider exists, if not exists, it will be fast fail
     */
    protected Boolean check;
    /**
     * Whether to eagle-init
     */
    protected Boolean init;
    /**
     * Whether to use generic interface
     */
    protected String generic;
    /**
     * Whether to find reference's instance from the current JVM
     */
    protected Boolean injvm;
    /**
     * Lazy create connection
     */
    protected Boolean lazy = false;
    protected String reconnect;
    protected Boolean sticky = false;
    /**
     * Whether to support event in stub.
     */
    
    protected Boolean stubevent;
    /**
     * The remote service version the customer side will reference
     */