Move merge manually text below merge widget 

Replace !1121 

Screenshot: 

#### Before

![Screenshot_2015-08-10_18.25.22](https://gitlab.com/gitlab-org/gitlab-ce/uploads/ac7df8dd03104b3b44c61b3bff709653/Screenshot_2015-08-10_18.25.22.png)


#### After

![Screenshot_2015-08-10_18.28.30](https://gitlab.com/gitlab-org/gitlab-ce/uploads/c92b8eaeadb842705577dba1f52b67e5/Screenshot_2015-08-10_18.28.30.png)



See merge request !1141