FELIX-4681 - fix parsing of single-digit ports:

- when you specify a port of `0` (which essentially is the same as
  specifying `*`), this causes an exception;
- added unit tests to cover this additional case.



git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1634867 13f79535-47bb-0310-9956-ffa450edef68