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 addParameter(String key, long value) {
        return addParameter(key, String.valueOf(value));
    }
    public URL addParameter(String key, float value) {
        return addParameter(key, String.valueOf(value));
    }
    public URL addParameter(String key, double value) {
        return addParameter(key, String.valueOf(value));
    }
    public URL addParameter(String key, Enum<?> value) {
        if (value == null) {
            return this;
        }
        return addParameter(key, String.valueOf(value));
    }
    public URL addParameter(String key, Number value) {
        if (value == null) {
            return this;
        }
        return addParameter(key, String.valueOf(value));
    }
    public URL addParameter(String key, CharSequence value) {
        if (value == null || value.length() == 0) {
            return this;
        }
        return addParameter(key, String.valueOf(value));
    }
    public URL addParameter(String key, String value) {
        if (StringUtils.isEmpty(key)
                || StringUtils.isEmpty(value)) {