Bug 32690: Reindent the serial collection template

Bug 32690: Reindent the serial collection template

This patch reindents the serial collection template so that it has
consistent indentation. These changes should have no visible effect on
the page.

To test, apply the patch and go to Serials -> Subscription detail ->
Serial collection. Everything should look normal. All tabs should work
correctly.

Viewing the diff while ignoring whitespace changes should show only
places where a line break was added.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>