lower version, for example 2.6.8
```properties
dubbo.provider.version=1.0
```

2.7.6 failed to recognize the provider url with 'default.version=1.0' key,  it only takes 'version.1.0' into consideration.

notify.put(key, service);
        Map<String, Map<String, String>> newRegister = UrlUtils.revertNotify(notify);
        Map<String, Map<String, String>> expectedRegister = new HashMap<String, Map<String, String>>();
        service.put("dubbo://127.0.0.1:20880/com.xxx.XxxService", "group=perf&version=1.0.0");
        expectedRegister.put("perf/dubbo.test.api.HelloService:1.0.0", service);
        assertEquals(expectedRegister, newRegister);
    }
    @Test
    public void testRevertNotify2() {
        String key = "perf/dubbo.test.api.HelloService:1.0.0";
        Map<String, Map<String, String>> notify = new HashMap<String, Map<String, String>>();
        Map<String, String> service = new HashMap<String, String>();
        service.put("dubbo://127.0.0.1:20880/com.xxx.XxxService", "group=perf&version=1.0.0");
        notify.put(key, service);
        Map<String, Map<String, String>> newRegister = UrlUtils.revertNotify(notify);
        Map<String, Map<String, String>> expectedRegister = new HashMap<String, Map<String, String>>();
        service.put("dubbo://127.0.0.1:20880/com.xxx.XxxService", "group=perf&version=1.0.0");
        expectedRegister.put("perf/dubbo.test.api.HelloService:1.0.0", service);
        assertEquals(expectedRegister, newRegister);
    }
    
    @Test
    public void testRevertForbid() {
        String service = "dubbo.test.api.HelloService";
        List<String> forbid = new ArrayList<String>();
        forbid.add(service);
        Set<URL> subscribed = new HashSet<URL>();
        subscribed.add(URL.valueOf("dubbo://127.0.0.1:20880/" + service + "?group=perf&version=1.0.0"));
        List<String> newForbid = UrlUtils.revertForbid(forbid, subscribed);
        List<String> expectForbid = new ArrayList<String>();