Description of problem:
Edit dc from web-console, add one command in single-line editor and save. Then edit it again, add one command, click "Add" and "Save". the new added command is not really saved  

Version-Release number of selected component (if applicable):
openshift v3.4.0.39

How reproducible:
Always

Steps to Reproduce:
1. oc run dc --image=aosqe/hello-openshift
2. From web console, go to dc edit page "https://xxx:8443/console/project/myproject/edit/dc/dc".
Click "advanced strategy options." and add a command "echo test" in Pre Lifecycle Hook, hit "Add" in the right of the input box and hit "Save"
3. Go to dc edit page again, click "advanced strategy options."
Add one command "echo test again" for the container, hit "Add" and then hit "Save"
4.1 Go to dc edit page again, click "advanced strategy options." and check the commands
4.2 oc describe dc/dc

Actual results:
4. New command in step 3 is not really saved
check on both web-console and cli command
# oc describe dc/dc
Strategy:    Rolling
  Pre-deployment hook (pod type, failure policy: Abort):
    Container:    dc
    Command:    echo test -> this is the end, no other command


Expected results:
4. New command in step 3 should be really saved.

Additional info:
This is a common issue, also reproduced in dc health check edit page.
Can only reproduced when ONE new command added.