Numerous doc files generate "redirect" warnings when running
"make linkcheck" simply warning that http:// is being mapped to
https://, so make those changes just to quiet the output from
that command.

Change-Id: I89d6ea0d8f402fcdaf6a117c9a6dea32cbd4b8f1
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>