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.

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.equalTo;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
public class UrlUtilsTest {
    String localAddress = "127.0.0.1";
    @Test
    public void testAddressNull() {
        assertNull(UrlUtils.parseURL(null, null));
    }
    @Test
    public void testParseUrl() {
        String address = "remote://root:alibaba@127.0.0.1:9090/dubbo.test.api";
        URL url = UrlUtils.parseURL(address, null);
        assertEquals(localAddress + ":9090", url.getAddress());
        assertEquals("root", url.getUsername());
        assertEquals("alibaba", url.getPassword());
        assertEquals("dubbo.test.api", url.getPath());
        assertEquals(9090, url.getPort());
        assertEquals("remote", url.getProtocol());
    }
    @Test
    public void testParseURLWithSpecial() {
        String address = "127.0.0.1:2181?backup=127.0.0.1:2182,127.0.0.1:2183";
        assertEquals("dubbo://" + address, UrlUtils.parseURL(address, null).toString());
    }
    @Test
    public void testDefaultUrl() {