### 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
this.interfaceClass = interfaceClass;
        setInterface(interfaceClass == null ? null : interfaceClass.getName());
    }
    public void setInterface(String interfaceName) {
        this.interfaceName = interfaceName;
        if (StringUtils.isEmpty(id)) {
            id = interfaceName;
        }
    }
    public T getRef() {
        return ref;
    }
    public void setRef(T ref) {
        this.ref = ref;
    }
    @Parameter(excluded = true)
    public String getPath() {
        return path;
    }
    public void setPath(String path) {
        checkPathName(PATH_KEY, path);
        this.path = path;
    }
    public List<MethodConfig> getMethods() {
        return methods;
    }
    // 
    @SuppressWarnings("unchecked")
    public void setMethods(List<? extends MethodConfig> methods) {
        this.methods = (List<MethodConfig>) methods;