### 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
private boolean shouldDelay() {
        Integer delay = getDelay();
        return delay != null && delay > 0;
    }
    @Override
    public Integer getDelay() {
        return (delay == null && provider != null) ? provider.getDelay() : delay;
    }
    protected synchronized void doExport() {
        if (unexported) {
            throw new IllegalStateException("The service " + interfaceClass.getName() + " has already unexported!");
        }
        if (exported) {
            return;
        }
        exported = true;
        if (StringUtils.isEmpty(path)) {
            path = interfaceName;
        }
        doExportUrls();
    }
    private void checkRef() {
        // 
        if (ref == null) {
            throw new IllegalStateException("ref not allow null!");
        }
        if (!interfaceClass.isInstance(ref)) {
            throw new IllegalStateException("The class "
                    + ref.getClass().getName() + " unimplemented interface "
                    + interfaceClass + "!");