Let update-rc.d set changed flag properly

When update-rc.d is used to enable/disable service, the changed flag was
always true (see #2189). This commit fixes that.

Signed-off-by: martin f. krafft <madduck@madduck.net>
Expand usage of Python 2.6 if statement

Syntax like "'foo' if bar else 'baz'" is not supported by all Python
versions targetted by Ansible. Hence we break it up.

Signed-off-by: martin f. krafft <madduck@madduck.net>
Merge pull request #3315 from madduck/fix-service-updatercd-changed

Let update-rc.d set changed flag properly