Remove need for 'uniq' not in macos list::util

[tseemann]

==> /usr/local/Cellar/snippy/4.2.1/bin/snippy-core --check
"uniq" is not exported by the List::Util module
Can't continue after import errors at /usr/local/Cellar/snippy/4.2.1/bin/snippy-core line 9.
BEGIN failed--compilation aborted at /usr/local/Cellar/snippy/4.2.1/bin/snippy-core line 9.
I forgot mac perl modules are ancient!

/usr/bin/perldoc List::Util
       use List::Util qw(first max maxstr min minstr reduce shuffle sum);
perldoc List::Util

        use List::Util qw(
          reduce any all none notall first

          max maxstr min minstr product sum sum0

          pairs unpairs pairkeys pairvalues pairfirst pairgrep pairmap

          shuffle uniq uniqnum uniqstr
        );