qa/589 - explain port 26, handle firewall rejection
qa/589 - explain port 26, handle firewall rejection

Different error message from some firewalls.

mbaldessari/pcp,adfernandes/pcp,wuliming/pcp,wuliming/pcp,andyvand/cygpcpfans,ryandoyle/pcp_original,andyvand/cygpcpfans,ryandoyle/pcp_original,tjanez/pcp,edwardt/pcp,andyvand/cygpcpfans,andyvand/cygpcpfans,edwardt/pcp,wuliming/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,aeg-aeg/pcpfans,adfernandes/pcp,andyvand/cygpcpfans,tjanez/pcp,prasincs/pcp,aeg-aeg/pcpfans,tjanez/pcp,aeg-aeg/pcpfans,adfernandes/pcp,ryandoyle/pcp_original,prasincs/pcp,edwardt/pcp,aeg-aeg/pcpfans,tjanez/pcp,ryandoyle/pcp_original,prasincs/pcp,edwardt/pcp,ryandoyle/pcp_original,tjanez/pcp,prasincs/pcp,mbaldessari/pcp,mbaldessari/pcp,mbaldessari/pcp,andyvand/cygpcpfans,edwardt/pcp,adfernandes/pcp,prasincs/pcp,edwardt/pcp,tjanez/pcp,wuliming/pcp,mbaldessari/pcp,edwardt/pcp,adfernandes/pcp,aeg-aeg/pcpfans,andyvand/cygpcpfans,prasincs/pcp,aeg-aeg/pcpfans,aeg-aeg/pcpfans,ryandoyle/pcp_original,prasincs/pcp,ryandoyle/pcp_original,edwardt/pcp,wuliming/pcp,wuliming/pcp,wuliming/pcp,aeg-aeg/pcpfans,mbaldessari/pcp,wuliming/pcp,tjanez/pcp,tjanez/pcp,ryandoyle/pcp_original,prasincs/pcp,andyvand/cygpcpfans