We will keep adding/removing options to our 'configure' script,
so for easier maintainability it makes sense to have CONFIGURE_ARGS
declared as one option per line. This way we can review diff easily
(or rebase/cherry-pick).

No logical change.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201108204535.2319870-6-philmd@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>