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.

public URL addParameters(String... pairs) {
        if (pairs == null || pairs.length == 0) {
            return this;
        }
        if (pairs.length % 2 != 0) {
            throw new IllegalArgumentException("Map pairs can not be odd number.");
        }
        Map<String, String> map = new HashMap<>();
        int len = pairs.length / 2;
        for (int i = 0; i < len; i++) {
            map.put(pairs[2 * i], pairs[2 * i + 1]);
        }
        return addParameters(map);
    }
    public URL addParameterString(String query) {
        if (StringUtils.isEmpty(query)) {
            return this;
        }
        return addParameters(StringUtils.parseQueryString(query));
    }
    public URL removeParameter(String key) {
        if (StringUtils.isEmpty(key)) {
            return this;
        }
        return removeParameters(key);
    }
    public URL removeParameters(Collection<String> keys) {
        if (CollectionUtils.isEmpty(keys)) {
            return this;
        }