Fix t/rules.t on darwin-2level / 5.12.5

  #   Failed test 'got correct rules'
  #   at t/rules.t line 22.
  #     Structures begin differing at:
  #          $got->[1] = 'return 0 unless +($_[1]->tx->remote_port || '') =~ /(?-xism:8000)/;'
  #     $expected->[1] = 'return 0 unless +($_[1]->tx->remote_port || '') =~ /(?^:8000)/;'
  # Looks like you failed 1 test of 1.
  t/rules.t ..........
Released version 0.44

       * Compatible with Mojolicious 5.0