Bug#4073 - Polycom VOIP phones unable to use FTPS data transfers.
Remove unnecessary comment.
The heuristic for disabling sendfile support when implicit FTPS is used does
not need to include the port number; having TLS negotiated at the time
of session initialization is enough.
Merge pull request #19 from proftpd/tls-implicitssl-download-bug4073

Bug#4073 - Polycom VOIP phones unable to use FTPS data transfers.