[4.0.0] regression - NumberFormatException: For input string: "$"

We have a test like this

  "throw an exception for invalid cron expression with unknown char" in {
      parse("* * * * $ ?") must throwA[IllegalArgumentException](
        Pattern.quote("Invalid chars in expression! Expression: $ Invalid chars: $")
      )
    }

but with 4.0.0 this now fails with a IllegalArgumentException with message java.lang.NumberFormatException: For input string: "$"' This is way to technical to show to an enduser

this seems to be a regression from #11 where this was fixed: https://github.com/jmrozanec/cron-utils/commit/7bb8f323d09a47776ae30a372ab721c32be80708#diff-6effbc1e4c5d8c95168d63f715564b44R149

Most of the tests only test for exceptions thrown without validating messages: https://github.com/jmrozanec/cron-utils/commit/7bb8f323d09a47776ae30a372ab721c32be80708#diff-b9ebcbf03bf1827c5a96cb483e84ea62R37

[jmrozanec]

Fix published in release 4.0.1

[jmrozanec]

@francisdb Fixed!