IniFileConfigurationSource.Commit() cannot handle empty value

[ChengTian]

Assume we have an ini file config.ini

; No value for this key
DefaultKey=

Then we do

var config = new IniFileConfigurationSource("config.ini");
config.Set("DefaultKey", "Value");
config.Commit();

The last line throws an exception because empty value is not handled properly. The expected behavior is that config.ini file is updated to

; No value for this key
DefaultKey=Value