deployment config controller doesn't sync, conformance flakes

[stevekuznetsov]

seen here

/data/src/github.com/openshift/origin/test/extended/deployments/deployments.go:577
the current deployment needs to have finished before attempting to trigger a new deployment through configuration change
Expected error:
    <*errors.errorString | 0xc8200ce130>: {
        s: "timed out waiting for the condition",
    }
    timed out waiting for the condition
not to have occurred

[mfojtik]

interesting, the seventh DC we triggered (and the one that failed) has this error:

I0804 16:09:00.952711   27136 controller.go:407] Error syncing deployment config extended-test-cli-deployment-qnffq-gqpmq/history-limit: Operation cannot be fulfilled on replicationcontrollers "history-limit-7": the object has been modified; please apply your changes to the latest version and try again

[0xmichalis]

@mfojtik do we need the retries on conflict you have in #10341?

[mfojtik]

@Kargakis will check.

[0xmichalis]

#10507 added retries on update conflicts in the deploymentconfig controller. Closing until we see it again.