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 float getPositiveParameter(String key, float defaultValue) {
        if (defaultValue <= 0) {
            throw new IllegalArgumentException("defaultValue <= 0");
        }
        float value = getParameter(key, defaultValue);
        return value <= 0 ? defaultValue : value;
    }
    public double getPositiveParameter(String key, double defaultValue) {
        if (defaultValue <= 0) {
            throw new IllegalArgumentException("defaultValue <= 0");
        }
        double value = getParameter(key, defaultValue);
        return value <= 0 ? defaultValue : value;
    }
    public long getPositiveParameter(String key, long defaultValue) {
        if (defaultValue <= 0) {
            throw new IllegalArgumentException("defaultValue <= 0");
        }
        long value = getParameter(key, defaultValue);
        return value <= 0 ? defaultValue : value;
    }
    public int getPositiveParameter(String key, int defaultValue) {
        if (defaultValue <= 0) {
            throw new IllegalArgumentException("defaultValue <= 0");
        }
        int value = getParameter(key, defaultValue);
        return value <= 0 ? defaultValue : value;
    }
    public short getPositiveParameter(String key, short defaultValue) {