"Cherry-pick" button doesn't always show up in a merged MR
### Summary
The "Cherry-pick" button shows up in a merged MR if repo setting is "Merge Commit" but not if repo setting is "Fast-forward Merge"
### Steps to reproduce
Have a repo configured to the "Merge Commit" setting
Make a merge request, merge it
Notice the "cherry pick button"
Change the repo setting to "Fast-forward Merge"
### Example Project
https://gitlab.com/cjcjameson/demo-cherry-pick-button-only-on-some-MR-screens/merge_requests/1
https://gitlab.com/cjcjameson/demo-cherry-pick-button-only-on-some-MR-screens/merge_requests/2
### What is the current *bug* behavior?
If a repo is configured for "Fast forward merge"
When I merge a MR
There's a big blank white area to the right of the name of the merge request (no button)
### What is the expected *correct* behavior?
If a repo is configured for "Fast forward merge"
When I merge a MR
Then I can click a button in the same screen to start a cherry-pick merge request
### Relevant logs and/or screenshots
When "Merge Commit" is the setting

When "Fast-forward Commit" is the setting --> no cherry-pick option!

#### Results of GitLab environment info
Gitlab EE 10.6.1
### Possible fixes
The workaround is to click through to the commit that went in, and in the ... (meatballs) menu in the upper right, there's an option to cherry-pick it. That works, it's just 3 more clicks and you don't even know it's an available option
issue