Duplicate lines in AdditionalConfiguration.php when saving new language file override twice

WHen saving a new language file override in the lfeditor backend module, a new line is written to the AdditionalConfiguration.pnp file. If the module is reloaded, it is somehow detected, that the line got written to the file, however if the module is NOT reloaded, but one clicks the save button twice, the same line gets written twice into the AdditionalConfiguration.php. This happens every time, the save button gets clicked again after creating a new locallang override without reloading the module.