Merge Request deployment link showing the wrong link
### Summary
I use gitlab-ci with a custom system deployment with basic scheme like `branch.env.domain.tld`
### Steps to reproduce
Open first MR `feature A` that'll create pipeline deployment to `1-feature-a.dev.domain.tld`
Create second MR `feature B` that'll create pipeline deployment to `2-feature-b.dev.domain.tld`
### What is the current *bug* behavior?
When reopen first MR, i show the link to de second MR
### What is the expected *correct* behavior?
I expect view the correct link in MR not the last run in the same environment
#### Results of GitLab environment info
<details>
<summary>Expand for output related to GitLab environment info</summary>
<pre>
GitLab 10.2.0
GitLab Shell 5.9.4
GitLab Workhorse v3.3.1
GitLab API v4
Gitaly 0.52.0
Git 2.13.6
Ruby 2.3.5p376
Rails 4.2.8
postgresql 9.6.5
</pre>
</details>
### Possible fixes
Simple permalink system should work
issue