Remove need_approval file if plan is clean

There is possible situation when we generated approval plan and then
disabled approvals which leads to update to pass. When we reactivate
approvals it is reported as new plan to approve, but there is no such
change planned, it's just a ghost of old plan. This ensures that we
remove plan when we have no new plan.
4 jobs for fixups in 12 minutes and 8 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed test #52545

00:11:07

passed test_busybox #52546

00:12:07

failed test #52520

00:00:44

failed test_busybox #52521

00:00:44