Makefile::AST::Evaluator: remove strange unicode char

This was causing test failures in pod.t since the pod doesn't declare encoding (thus defaulting to ascii).

    t/99-pod.t ........... 1/13
    #   Failed test 'POD test for blib/lib/Makefile/AST/Evaluator.pm'
    #   at /usr/share/perl5/Test/Pod.pm line 186.
    Wide character in print at /home/olof/src/github/agentzh/makefile-parser-pm/inc/Test/Builder.pm line 1471.
    # blib/lib/Makefile/AST/Evaluator.pm (338): Non-ASCII character seen before =encoding in 'C<--ignore-errors>，It's'. Assuming UTF-8
    # Looks like you failed 1 test of 13.
    t/99-pod.t ........... Dubious, test returned 1 (wstat 256, 0x100)

I don't know if the choice was intentional, but I _guess_ not; it does look a lot like a ,.