Extension - default config value is empty string

[kravcik]

Version: 3.0.10

Bug Description

Cannot send empty string, works in v3.0.9. Alternative null works in both versions.

Simplifiend code:

pf beforeCompile()
{
  $builder->getDefinitionByType(UserFormFactory::class)
    ->getResultDefinition()
    ->addSetup('setExpiration', ['']); // [null] works
}

Expected Behavior

Should be possible pass empty string. Or if this is intended, should throw exception and suggest null instead of ''.