Update SCPTask to also use delegate_to
Update SCPTask to also use delegate_to

This brings both our FTP / SCP task inline using the same logic for
delegate_to.

Change-Id: I234069838e3feb2047b32dbbdb92e6ce7acc5077
Signed-off-by: Paul Belanger <e7139c8e6c4ea75cc1c287ce081b2dc0f3ab39ec@redhat.com>

gooddata/zuul,wikimedia/integration-zuul,gooddata/zuul,wikimedia/integration-zuul,gooddata/zuul,gooddata/zuul,wikimedia/integration-zuul,gooddata/zuul,wikimedia/integration-zuul