CDP: deal with special hostname SIP$MAC

this patch also fix a regression introduce by 252a52bf24af77b8b046.
adjust the test for 78df01bee0

see commit:78df01bee01306257fdc9
show up Net::SSLeay on STDERR if debug=3
Merge branch 'master' of git+ssh://forge.fusioninventory.org/git/fusioninventory/agent